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rfc:rfc8795



Internet Engineering Task Force (IETF) X. Liu Request for Comments: 8795 Volta Networks Category: Standards Track I. Bryskin ISSN: 2070-1721 Futurewei Technologies, Inc.

                                                             V. Beeram
                                                               T. Saad
                                                      Juniper Networks
                                                               H. Shah
                                                                 Ciena
                                                   O. Gonzalez de Dios
                                                            Telefonica
                                                           August 2020
      YANG Data Model for Traffic Engineering (TE) Topologies

Abstract

 This document defines a YANG data model for representing, retrieving,
 and manipulating Traffic Engineering (TE) Topologies.  The model
 serves as a base model that other technology-specific TE topology
 models can augment.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 7841.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 https://www.rfc-editor.org/info/rfc8795.

Copyright Notice

 Copyright (c) 2020 IETF Trust and the persons identified as the
 document authors.  All rights reserved.
 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (https://trustee.ietf.org/license-info) in effect on the date of
 publication of this document.  Please review these documents
 carefully, as they describe your rights and restrictions with respect
 to this document.  Code Components extracted from this document must
 include Simplified BSD License text as described in Section 4.e of
 the Trust Legal Provisions and are provided without warranty as
 described in the Simplified BSD License.

Table of Contents

 1.  Introduction
   1.1.  Terminology
   1.2.  Tree Structure
   1.3.  Prefixes in Data Node Names
 2.  Characterizing TE Topologies
 3.  Modeling Abstractions and Transformations
   3.1.  TE Topology
   3.2.  TE Node
   3.3.  TE Link
   3.4.  Transitional TE Link for Multi-layer Topologies
   3.5.  TE Link Termination Point (LTP)
   3.6.  TE Tunnel Termination Point (TTP)
   3.7.  TE Node Connectivity Matrix
   3.8.  TTP Local Link Connectivity List (LLCL)
   3.9.  TE Path
   3.10. TE Inter-layer Lock
   3.11. Underlay TE Topology
   3.12. Overlay TE Topology
   3.13. Abstract TE Topology
 4.  Model Applicability
   4.1.  Native TE Topologies
   4.2.  Customized TE Topologies
   4.3.  Merging TE Topologies Provided by Multiple Providers
   4.4.  Dealing with Multiple Abstract TE Topologies Provided by
         the Same Provider
 5.  Modeling Considerations
   5.1.  Network Topology Building Blocks
   5.2.  Technology-Agnostic TE Topology Model
   5.3.  Model Structure
   5.4.  Topology Identifiers
   5.5.  Generic TE Link Attributes
   5.6.  Generic TE Node Attributes
   5.7.  TED Information Sources
   5.8.  Overlay/Underlay Relationship
   5.9.  Templates
   5.10. Scheduling Parameters
   5.11. Notifications
 6.  Guidance for Writing Technology-Specific TE Topology
         Augmentations
 7.  TE Topology YANG Module
 8.  Security Considerations
 9.  IANA Considerations
 10. References
   10.1.  Normative References
   10.2.  Informative References
 Appendix A.  Complete Model Tree Structure
 Appendix B.  Companion YANG Data Model for Non-NMDA-Compliant
         Implementations
   B.1.  TE Topology State YANG Module
 Appendix C.  Example: YANG Data Model for Technology-Specific
         Augmentations
 Acknowledgments
 Contributors
 Authors' Addresses

1. Introduction

 The Traffic Engineering Database (TED) is an essential component of
 Traffic Engineered (TE) systems that are based on MPLS-TE [RFC2702]
 and GMPLS [RFC3945].  The TED is a collection of all TE information
 about all TE nodes and TE links in the network.  The TE topology is a
 schematic arrangement of TE nodes and TE links present in a given
 TED.  There could be one or more TE topologies present in a given TE
 system.  A TE topology is the topology on which path computational
 algorithms are run to compute TE paths.
 This document defines a YANG data model [RFC7950] for representing,
 retrieving, and manipulating TE topologies.  This model contains
 technology-agnostic TE topology building blocks that can be augmented
 and used by other technology-specific TE topology models.

1.1. Terminology

 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
 "OPTIONAL" in this document are to be interpreted as described in
 BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
 capitals, as shown here.
 We assume that the reader is familiar with the general body of work
 captured in currently available RFCs related to Traffic Engineering.
 [RFC7926] serves as a good starting point for those who may be less
 familiar with RFCs related to Traffic Engineering.
 Some of the key terms used in this document are as follows:
 TED:  The Traffic Engineering Database (TED) is a collection of all
    TE information about all TE nodes and TE links in a given network.
 TE topology:  The TE topology is a schematic arrangement of TE nodes
    and TE links in a given TED.  It forms the basis for a graph
    suitable for TE path computations.
 Native TE topology:  A Native TE topology is a topology that is
    native to a given provider network.  A Native TE topology could be
    discovered via various routing protocols and/or subscribe/publish
    techniques.  This is the topology on which path computational
    algorithms are run to compute TE paths.
 Customized TE topology:  A Customized TE topology is a custom
    topology that is produced by a provider for a given client.  This
    topology typically makes abstractions on the provider's Native TE
    topology and is provided to the client.  The client receives the
    Customized TE topology and merges it into the client's Native TE
    topology.  The client's path computational algorithms aren't
    typically run on the Customized TE topology; they are run on the
    client's Native TE topology after the merge.

1.2. Tree Structure

 A simplified graphical representation of the data model is presented
 in Appendix A of this document.  The tree format defined in [RFC8340]
 is used for the YANG data model tree representation.

1.3. Prefixes in Data Node Names

 In this document, names of data nodes and other data model objects
 are prefixed using the standard prefix associated with the
 corresponding YANG imported modules, as shown in Table 1.
           +==========+=======================+===========+
           | Prefix   | YANG Module           | Reference |
           +==========+=======================+===========+
           | yang     | ietf-yang-types       | [RFC6991] |
           +----------+-----------------------+-----------+
           | inet     | ietf-inet-types       | [RFC6991] |
           +----------+-----------------------+-----------+
           | nw       | ietf-network          | [RFC8345] |
           +----------+-----------------------+-----------+
           | nt       | ietf-network-topology | [RFC8345] |
           +----------+-----------------------+-----------+
           | te-types | ietf-te-types         | [RFC8776] |
           +----------+-----------------------+-----------+
           Table 1: Prefixes and Corresponding YANG Modules

2. Characterizing TE Topologies

 The data model defined by this document takes the following
 characteristics of TE topologies into account:
  • The TE topology is an abstract control-plane representation of the

data-plane topology. Hence, attributes specific to the data plane

    must make their way into the corresponding TE topology modeling.
    The TE topology is comprised of dynamic autodiscovered data as
    well as fairly static data associated with data-plane nodes and
    links.  The dynamic data, such as unreserved bandwidth available
    on data-plane links, may change frequently.  The static data, such
    as layer network identification, switching and adaptation
    capabilities and limitations, fate-sharing, and administrative
    colors, rarely changes.  It is possible for a single TE topology
    to encompass TE information at multiple switching layers.
  • TE topologies are protocol independent. Information about

topological elements may be learned via link-state protocols, but

    the topology can exist without being dependent on any particular
    protocol.
  • The TE topology may not be congruent with the routing topology in

a given TE system. The routing topology is constructed based on

    routing adjacencies.  There isn't always a one-to-one association
    between a TE link and a routing adjacency.  For example, the
    presence of a TE link between a pair of nodes doesn't necessarily
    imply the existence of a routing adjacency between these nodes.
    To learn more, see [TEAS-TOPO] and [YANG-L3].
  • Each TE topological element has at least one information source

associated with it. In some scenarios, there could be more than

    one information source associated with any given topological
    element.
  • TE topologies can be hierarchical. Each node and link of a given

TE topology can be associated with a respective underlay topology.

    This means that each node and link of a given TE topology can be
    associated with an independent stack of supporting TE topologies.
  • TE topologies can be customized. TE topologies of a given network

presented by the network provider to its client could be

    customized on a per-client-request basis.  This customization
    could be performed by the provider, by the client, or by
    provider/client negotiation.  The relationship between a
    customized topology and the provider's native topology could be
    captured as hierarchical (overlay/underlay), but otherwise the two
    topologies are decoupled from each other.  A customized topology
    is presented to the client, while the provider's native topology
    is known in its entirety to the provider itself.

3. Modeling Abstractions and Transformations

3.1. TE Topology

 A TE topology is a Traffic Engineering representation of one or more
 layers of network topologies.  A TE topology is comprised of TE nodes
 (TE graph vertices) interconnected via TE links (TE graph edges).  A
 TE topology is mapped to a TE graph.

3.2. TE Node

 A TE node is an element of a TE topology, presented as a vertex on a
 TE graph.  A TE node represents one or several nodes, or a fraction
 of a node, which can be a switch or router that is physical or
 virtual.  A TE node belongs to and is fully defined in exactly one TE
 topology.  A TE node is assigned a unique ID within the TE topology
 scope.  TE node attributes include information related to the
 data-plane aspects of the associated node(s) (e.g., connectivity
 matrix), as well as configuration data (such as the TE node name).  A
 given TE node can be reached on the TE graph over one of the TE links
 terminated by the TE node.
 Multi-layer TE nodes providing switching functions at multiple
 network layers are an example where a physical node can be decomposed
 into multiple logical TE nodes, which are fractions of the physical
 node.  Some of these (logical) TE nodes may reside in the client-
 layer TE topology, while the remaining TE nodes belong to the server-
 layer TE topology.
 In Figure 1, Node-1, Node-2, and Node-3 are TE nodes.
                              | +---+          __
                              | |   | TE Node  \/ TTP  o LTP
                              | +---+
                              |
                              | ----- TE Link
                              | ***** Node Connectivity Matrix,
                              |       TTP Local Link Connectivity
                              | @@@@@ TE Tunnel
                              o----------------------------------
    Node-1                                            Node-3
 +------------+                                    +------------+
 |    TTP-1   |                                    |    TTP-1   |
 |LTP  __     |           TE-Tunnel-1              |     __     |
 |-6   \/@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\/     |
 o    *  *    oLTP-1           Node-2         LTP-6o    *  *    o
 |   *    *   |           +------------+           |   *    *   |
 |  * TTP-2*  |           |            |           |  * TTP-2*  |
 | *   __   * |LTP-2 LTP-6|            |LTP-1 LTP-5| *   __   * |
 o*    \/    *o-----------o************o-----------o*    \/    *o
 |LTP *  *    | Link-12   |          * | Link-23   |    *  *    |
 |-5 *    *   |      LTP-5|        *   |LTP-2      |   *    *   |
 +--o------o--+           o************o           +--o------o--+
  LTP-4  LTP-3            | *   *    * |            LTP-4  LTP-3
                          |  **     *  |
                          +--o------o--+
                           LTP-4  LTP-3
 LTP: Link Termination Point
 TTP: Tunnel Termination Point
              Figure 1: TE Topology Modeling Abstractions

3.3. TE Link

 A TE link is an element of a TE topology, presented as an edge on a
 TE graph.  The arrows on an edge indicate one or both directions of
 the TE link.  When there are a pair of parallel links of opposite
 directions, an edge without arrows is also used.  A TE link
 represents one or several (physical) links or a fraction of a link.
 A TE link belongs to and is fully defined in exactly one TE topology.
 A TE link is assigned a unique ID within the TE topology scope.  TE
 link attributes include parameters related to the data-plane aspects
 of the associated link(s) (unreserved bandwidth, resource maps /
 resource pools, etc.), as well as the configuration data (remote
 node IDs / link IDs, Shared Risk Link Groups (SRLGs), administrative
 colors, etc.).  A TE link is connected to a TE node, terminating the
 TE link via exactly one TE Link Termination Point (LTP).
 In Figure 1, Link-12 and Link-23 are TE links.

3.4. Transitional TE Link for Multi-layer Topologies

 Networks are typically composed of multiple network layers where one
 or multiple signals in the client-layer network can be multiplexed
 and encapsulated into a server-layer signal [RFC5212] [G.805].  The
 server-layer signal can be carried in the server-layer network across
 multiple nodes until the server-layer signal is terminated and the
 client-layer signals reappear in the node that terminates the server-
 layer signal.  Examples of multi-layer networks include (1) IP over
 MPLS over Ethernet and (2) low-order Optical Data Unit-k (ODUk)
 signals multiplexed into a high-order ODUl (l>k) carried over an
 Optical Channel (OCh) signal in an Optical Transport Network (OTN) as
 defined in [G.872] and [G.709].
 TE links as defined in Section 3.3 can be used to represent links
 within a network layer.  In the case of a multi-layer network, TE
 nodes and TE links only allow the representation of each network
 layer as a separate TE topology.  Each of these single-layer TE
 topologies would be isolated from their client and their server-layer
 TE topology, if present.  The highest network layer and the lowest
 network layer in the hierarchy only have a single adjacent layer
 below or above, respectively.  Multiplexing client-layer signals and
 encapsulating them into a server-layer signal require a function that
 is provided inside a node (typically realized in hardware).  This
 function is also called "layer transition".
 One of the key requirements for path computation is to be able to
 calculate a path between two endpoints across a multi-layer network
 based on the TE topology representing this multi-layer network.  This
 means that an additional TE construct is needed that represents
 potential layer transitions in the multi-layer TE topology that
 connects the TE topologies representing each separate network layer.
 The so-called transitional TE link is such a construct, and it
 represents the layer transition function residing inside a node that
 is decomposed into multiple logical nodes that are represented as TE
 nodes (also see [G.8080] for the definition of a transitional link
 for the OTN).  Hence, a transitional TE link connects a client-layer
 node with a server-layer node.  A TE link as defined in Section 3.3
 has LTPs of exactly the same kind on each link end, whereas the
 transitional TE link has client-layer LTPs on the client side of the
 transitional link and, in most cases, a single server-layer LTP on
 the server side.  It should be noted that transitional links are a
 helper construct in the multi-layer TE topology and they only exist
 as long as they are not in use, as they represent potential
 connectivity.  When the server-layer trail has been established
 between the server-layer LTP of two transitional links in the server-
 layer network, the resulting client-layer link in the data plane will
 be represented as a normal TE link in the client-layer topology.  The
 transitional TE links will reappear when the server-layer trail has
 been torn down.
                              |                 |
                              | +---+          ---
                              | |   | TE Node  \ / Transitional
                              | +---+           |  Link
                              |
                              | ----- Client-Layer Link
                              | ===== Server-Layer Link
                              | ***** Layer Boundary
                              o----------------------------------
    +-------------------+
    | +-------+         |                          +-------+
 -----|Client-|------+  |             Client- -----|Client-|
    | |Layer  |---+  |  |             Layer        |Layer  |
 -----|Switch |-+ |  |  |             Links   -----|Node   |
    | +------ + | |  |  |                          +-------+
    |           | |  |  | Client                    | |  |
    |           | | ---_| Layer                     --- ---
 ***|***********|*| \ /*|***************************\ /*\ /****
    |           ---  |  | Server       Transitional  |   |
    |    Layer  \ /  |  | Layer               Links  |   |
    |    Term.   |   |  |                            |   |
    |            |   |  |                            |   |
    |         +-------+ |                          +-------+
 =============|Server-|=====           Server- ====|Server-|====
    |         |Layer  | |              Layer       |Layer  |
 =============|Switch |=====           Links   ====|Node   |====
    |         +-------+ |                          +-------+
    +-------------------+
     Physical Node View                       TE Topology View
       Figure 2: Modeling a Multi-layer Node (Dual-layer Example)

3.5. TE Link Termination Point (LTP)

 A TE Link Termination Point (LTP) is a conceptual point of connection
 of a TE node to one of the TE links, terminated by the TE node.
 Cardinality between an LTP and the associated TE link is 1:0..1.
 In Figure 1, Node-2 has six LTPs: LTP-1 through LTP-6.

3.6. TE Tunnel Termination Point (TTP)

 A TE Tunnel Termination Point (TTP) is an element of a TE topology
 representing one or several potential transport service termination
 points (i.e., service client adaptation points, such as a WDM/OCh
 transponder).  ("WDM" stands for "Wavelength Division Multiplexing".)
 A TTP is associated with (hosted by) exactly one TE node.  A TTP is
 assigned a unique ID within the TE node scope.  Depending on the TE
 node's internal constraints, a given TTP hosted by the TE node could
 be accessed via one, several, or all TE links terminated by the TE
 node.
 In Figure 1, Node-1 has two TTPs: TTP-1 and TTP-2.

3.7. TE Node Connectivity Matrix

 A TE node connectivity matrix is a TE node's attribute describing the
 TE node's switching limitations in the form of valid switching
 combinations of the TE node's LTPs (see below).  From the point of
 view of a potential TE path arriving at the TE node at a given
 inbound LTP, the node's connectivity matrix describes valid
 (permissible) outbound LTPs from which the TE path can leave the TE
 node.
 In Figure 1, the connectivity matrix on Node-2 is as follows:
 {<LTP-6, LTP-1>, <LTP-5, LTP-2>, <LTP-5, LTP-4>, <LTP-4, LTP-1>,
 <LTP-3, LTP-2>}

3.8. TTP Local Link Connectivity List (LLCL)

 A TTP Local Link Connectivity List (LLCL) is a list of TE links
 terminated by the TE node hosting a TTP, to which the TTP could be
 connected.  From the point of view of the potential TE path of a
 connection, an LLCL provides a list of valid TE links the TE path
 needs to start/stop on for the connection to be successfully
 terminated on a TTP.
 In Figure 1, the LLCL on Node-1 is as follows:
 {<TTP-1, LTP-5>, <TTP-1, LTP-2>, <TTP-2, LTP-3>, <TTP-2, LTP-4>}

3.9. TE Path

 A TE path is an ordered list of TE links and/or TE nodes on the TE
 topology graph; this path interconnects a pair of TTPs to be used by
 a potential connection.  For example, TE paths could be a product of
 successful path computation performed for a given transport service.
 In Figure 1, the TE path for TE-Tunnel-1 is as follows:
 {Node-1:TTP-1, Link-12, Node-2, Link-23, Node-3:TTP-1}

3.10. TE Inter-layer Lock

 A TE inter-layer lock is a modeling concept describing adaptation
 relationships between the client layer and the server layer and hence
 is important for multi-layer Traffic Engineering.  It is an
 association of M client-layer LTPs and N server-layer TTPs, within
 which data arriving at any of the client-layer LTPs could be adopted
 onto any of the server-layer TTPs.  A TE inter-layer lock is
 identified by an inter-layer lock ID, which is unique across all TE
 topologies provided by the same provider.  The client-layer LTPs and
 the server-layer TTPs associated within a given TE inter-layer lock
 are annotated with the same inter-layer lock ID attribute.
 In Figure 3, a TE inter-layer lock with an ID of IL-1 associates six
 client-layer LTPs (C-LTP-1 through C-LTP-6) with two server-layer
 TTPs (S-TTP-1 and S-TTP-2).  They all have the same attribute -- TE
 inter-layer lock ID IL-1, which is the only thing that indicates the
 association.  A given LTP may have zero, one, or more inter-layer
 lock IDs.  In the latter case, this means that the data arriving at
 the LTP may be adopted onto any of the TTPs associated with all
 specified inter-layer locks.  For example, C-LTP-1 could have two
 inter-layer lock IDs -- IL-1 and IL-2.  This would mean that C-LTP-1
 for adaptation purposes could use not just the TTPs associated with
 inter-layer lock IL-1 (i.e., S-TTP-1 and S-TTP-2 in the figure) but
 any of the TTPs associated with inter-layer lock IL-2 as well.
 Likewise, a given TTP may have one or more inter-layer lock IDs,
 meaning that it can offer the adaptation service to any of the
 client-layer LTPs with an inter-layer lock ID matching one of its
 own.  Additionally, each TTP has an unreserved adaptation bandwidth
 attribute, which announces its remaining adaptation resources that
 are sharable between all potential client-layer LTPs.
                              | +---+          __
                              | |   | TE Node  \/ TTP  o LTP
                              | +---+
                              |
                              | ----- TE Link
                              | ***** TTP Local Link Connectivity
                              o----------------------------------
           (IL-1) C-LTP-1 +------------+   C-LTP-2 (IL-1)
                  --------O   (IL-1)   O--------
           (IL-1) C-LTP-3 |   S-TTP-1  |   C-LTP-4 (IL-1)
                  --------O     __     0--------
           (IL-1) C-LTP-5 |    *\/*    |   C-LTP-6 (IL-1)
                  --------O   *    *   O--------
                          |  *(IL-1)*  |
                  S-LTP-3 | * S-TTP-2* |   S-LTP-4
                  --------o*    __    *o--------
                          |    *\/*    |
                          |   *    *   |
                          +--o------o--+
                     S-LTP-1 |      | S-LTP-2
             Figure 3: TE Inter-layer Lock ID Associations
 LTPs and TTPs associated within the same TE inter-layer lock may be
 hosted by the same (hybrid, multi-layer) TE node or multiple TE nodes
 located in the same or separate TE topologies.  The latter case is
 especially important, since TE topologies of different layer networks
 could be modeled by separate augmentations of the basic (common to
 all layers) TE topology model.

3.11. Underlay TE Topology

 An underlay TE topology is a TE topology that serves as a base for
 the construction of overlay TE topologies.

3.12. Overlay TE Topology

 An overlay TE topology is a TE topology that is constructed based on
 one or more underlay TE topologies.  Each TE node of the overlay TE
 topology represents an arbitrary segment of an underlay TE topology;
 each TE link of the overlay TE topology represents an arbitrary TE
 path in one of the underlay TE topologies.  The overlay TE topology
 and the supporting underlay TE topologies may represent distinct
 layer networks (e.g., OTN/ODUk and WDM/OCh, respectively) or the same
 layer network.

3.13. Abstract TE Topology

 An abstract TE topology is a topology that contains abstract
 topological elements (nodes, links, TTPs).  An abstract TE topology
 is an overlay TE topology created by a topology provider and
 customized for a topology provider's client based on one or more of
 the provider's Native TE topologies (underlay TE topologies), the
 provider's policies, and the client's preferences.  For example, a
 first-level topology provider (such as a domain controller) can
 create an abstract TE topology for its client (e.g., a multi-domain
 service coordinator) based on one or more of the provider's Native TE
 topologies, local policies/profiles, and the client's TE topology
 configuration requests.
 Figure 4 shows an example of an abstract TE topology.
                              | +---+
                              | |   | TE Node
                              | +---+
                              | ----- TE Link
                              o----------------------------------
   +---+              +---+
   |S3 |              |S5 |
   +---+\           / +---+
         \         /
          \       /
           \+---+/                +---+
           /|AN1|\----------------|S8 |
          / +---+ \               +---+
   +---+ /         \ +---+
   |S9 |             |S11|
   +---+             +---+
         Abstract TE Topology
          +---+                    +---+
          |S1 |--------------------|S2 |
          +---+                    +---+
           /                          \
          /                            \
   +---+ /                  +---+       \ +---+
   |S3 |--------------------|S4 |---------|S5 |
   +---+\                   +---+         +---+
         \                      \             \
          \                      \             \
           \+---+                 +---+         +---+
           /|S6 |\                |S7 |---------|S8 |
          / +---+ \               +---+\       /+---+
   +---+ /         \ +---+              +---+ /
   |S9 |-------------|S10|--------------|S11|/
   +---+             +---+              +---+
         Native TE Topology
                     Figure 4: Abstract TE Topology

4. Model Applicability

4.1. Native TE Topologies

 The model discussed in this document can be used to represent and
 retrieve Native TE topologies on a given TE system.
 Consider the network topology depicted in Figure 5.  R1 .. R9 are
 nodes representing routers.  An implementation MAY choose to
 construct a Native TE topology using all nodes and links present in
 the given TED as depicted in Figure 6.  The data model defined in
 this document can be used to represent and retrieve this TE topology.
                              | +---+
                              | |   | TE Node
                              | +---+
                              | ----- TE Link
                              o----------------------------------
   +---+       +---+        +---+         +---+         +---+
   | R1|-------| R2|--------| R3|---------| R4|---------| R5|
   +---+       +---+        +---+         +---+         +---+
     |                      /   \         /   \         /
     |                     /     \       /     \       /
     |                    /       \     /       \     /
     |                   /         \   /         \   /
     |                  /           \ /           \ /
   +---+             +---+         +---+         +---+
   | R6|-------------| R7|         | R8|---------| R9|
   +---+             +---+         +---+         +---+
                   Figure 5: Example Network Topology
  1. ————–

| Native | | [ ] TE Node

        | TE Topology |                   |  +++ TE Link
        ---------------                   o--------------
    [R1] ++++ [R2] ++++ [R3] ++++ [R4] ++++ [R5]
      +                +    +    +    +    +
      +               +      +  +      +  +
      +              +        ++        ++
    [R6] +++++++++ [R7]      [R8] ++++ [R9]
            Figure 6: Native TE Topology as Seen on Node R3
 Consider the case where the topology is split in a way that some
 nodes participate in OSPF-TE while others participate in ISIS-TE
 (Figure 7).  An implementation MAY choose to construct separate TE
 topologies based on the information source.  The Native TE topologies
 constructed using only nodes and links that were learned via a
 specific information source are depicted in Figure 8.  The data model
 defined in this document can be used to represent and retrieve these
 TE topologies.
                                   :
 TE Info Distributed via ISIS-TE   :  TE Info Distributed via OSPF-TE
                                   :
        +---+       +---+        +---+         +---+         +---+
        | R1|-------| R2|--------| R3|---------| R4|---------| R5|
        +---+       +---+        +---+         +---+         +---+
          |                      / : \         /   \         /
          |                     /  :  \       /     \       /
          |                    /   :   \     /       \     /
          |                   /    :    \   /         \   /
          |                  /     :     \ /           \ /
        +---+             +---+    :    +---+         +---+
        | R6|-------------| R7|    :    | R8|---------| R9|
        +---+             +---+    :    +---+         +---+
                                   :
                Figure 7: Example Split Network Topology
  1. ———————- : ———————–

|Native TE Topology | : |Native TE Topology |

         |Info-Source: ISIS-TE |   :  |Info-Source: OSPF-TE |
         -----------------------   :  -----------------------
                                   :
          [R1] ++++ [R2] ++++ [R3] : [R3'] ++++ [R4] ++++ [R5]
           +                +      :      +    +    +    +
           +               +       :       +  +      +  +
           +              +        :        ++        ++
          [R6] +++++++++ [R7]      :       [R8] ++++ [R9]
           Figure 8: Native TE Topologies as Seen on Node R3
 Similarly, the data model can be used to represent and retrieve a TE
 topology that is constructed using only nodes and links that belong
 to a particular technology layer.  The data model is flexible enough
 to represent and retrieve many such Native TE topologies.

4.2. Customized TE Topologies

 A Customized TE topology is a topology that was modified by the
 provider to honor a particular client's requirements or preferences.
 The model discussed in this document can be used to represent,
 retrieve, and manipulate Customized TE topologies.  The model allows
 the provider to present the network in abstract TE terms on a
 per-client basis.  These customized topologies contain sufficient
 information for the client to compute and select paths according to
 its policies.
 Consider the network topology depicted in Figure 9.  This is a
 typical packet optical transport deployment scenario where the WDM-
 layer network domain serves as a server network domain providing
 transport connectivity to the packet-layer network domain (client
 network domain).  Nodes R1, R2, R3, and R4 are IP routers that are
 connected to an optical WDM transport network.  A, B, C, D, E, and F
 are WDM nodes that constitute the server network domain.
                                | +---+            /-\
                                | |   | Router    (   ) WDM
                                | +---+ Node       \-/  Node
                                |
                                o----------------------------
   +---+        /-\          /-\           /-\          +---+
   | R1|-------( A )--------( C )---------( E )---------| R3|
   +---+        \-/          \-/           \-/          +---+
                            /   \         /   \
                           /     \       /     \
                          /       \     /       \
                         /         \   /         \
                        /           \ /           \
       +---+          /-\           /-\           /-\          +---+
       | R2|---------( B )---------( D )---------( F )---------| R4|
       +---+          \-/           \-/           \-/          +---+
               Figure 9: Example Packet Optical Topology
 The goal here is to augment the client's TE topology with a
 Customized TE topology provided by the WDM network.  Given the
 availability of the paths A-E, B-F, and B-E (Figure 10), a Customized
 TE topology as depicted in Figure 11 is provided to the client.  This
 Customized TE topology is merged with the client's Native TE
 topology, and the resulting topology is depicted in Figure 12.
                                          | *****  B-F WDM Path
                                          | @@@@@  B-E WDM Path
                                          | $$$$$  A-E WDM Path
                                          o--------------------
   +---+        /-\ $$$$$$$$ /-\ $$$$$$$$$ /-\          +---+
   | R1|-------( A )--------( C )---------( E )---------| R3|
   +---+        \-/         @\-/ @@@@@@@@@ \-/          +---+
                           @/   \         /   \
                          @/     \       /     \
                         @/       \     /       \
                        @/         \   /         \
                       @/           \ /           \
       +---+          /-\ ********* /-\ ********* /-\          +---+
       | R2|---------( B )---------( D )---------( F )---------| R4|
       +---+          \-/           \-/           \-/          +---+
              Figure 10: Paths within the Provider Domain
               ++++++++ [A] ++++++++++++++++++++ [E] +++++++++
                                            +++++
                                        ++++
                                    ++++
                                ++++
                            ++++
               ++++++++ [B] ++++++++++++++++++++ [F] +++++++++
        Figure 11: Customized TE Topology Provided to the Client
          [R1] ++++++++ [A] ++++++++++++++++++++ [E] +++++++++ [R3]
                                            +++++
                                        ++++
                                    ++++
                                ++++
                            ++++
          [R2] ++++++++ [B] ++++++++++++++++++++ [F] +++++++++ [R4]
             Figure 12: Customized TE Topology Merged with
                    the Client's Native TE Topology
 The data model defined in this document can be used to represent,
 retrieve, and manipulate the Customized TE topology depicted in
 Figure 11.
 A Customized TE topology is not necessarily an abstract TE topology.
 The provider may produce, for example, an abstract TE topology of a
 certain type (a single-abstract-node-with-connectivity-matrix
 topology, a border-nodes-connected-via-mesh-of-abstract-links
 topology, etc.) and expose it to all or some clients in the
 expectation that the clients will use it without customization.  On
 the other hand, a client may request a customized version of the
 provider's Native TE topology (e.g., by requesting the removal of TE
 links that belong to certain layers, are too slow, are not protected,
 and/or have a certain affinity).  Note that the resulting TE topology
 will not be abstract (because it will not contain abstract elements)
 but will be customized (modified upon the client's instructions).
 The client ID field in the TE topology identifier (Section 5.4)
 indicates which client the TE topology is customized for.  Although
 an authorized client MAY receive a TE topology with the client ID
 field matching some other client, the client can customize only TE
 topologies with the client ID field either set to 0 or matching the
 ID of the client in question.  If the client starts the
 reconfiguration of a topology, its client ID will be automatically
 set in the topology ID field for all future configurations and
 updates with regard to the topology in question.
 The provider, by setting its own ID in the client ID field of the
 topology ID, MAY tell the client that a given TE topology cannot be
 renegotiated.
 Even though this data model allows the access of TE topology
 information across clients, implementations MAY restrict access for
 particular clients to particular data fields.  The Network
 Configuration Access Control Model (NACM) [RFC8341] provides such a
 mechanism.

4.3. Merging TE Topologies Provided by Multiple Providers

 A client may receive TE topologies provided by multiple providers,
 each of which manages a separate domain of a multi-domain network.
 In order to make use of said topologies, the client is expected to
 merge the provided TE topologies into one or more of its own Native
 TE topologies, each of which homogeneously represents the multi-
 domain network.  This makes it possible for the client to select end-
 to-end TE paths for its services traversing multiple domains.
 In particular, the process of merging TE topologies includes:
  • Identifying neighboring domains and locking their topologies

horizontally by connecting their inter-domain open-ended TE links.

  • Renaming TE node IDs, link IDs, and SRLG IDs to IDs allocated from

a separate namespace; this is necessary because all TE topologies

    are considered to be, generally speaking, independent, and clashes
    among TE node IDs, link IDs, or SRLG IDs are possible.
  • Locking, vertically, TE topologies associated with different layer

networks, according to provided topology inter-layer locks; this

    is done to facilitate inter-layer path computations across
    multiple TE topologies provided by the same topology provider.
 Figure 13 illustrates the process whereby the client merges the TE
 topologies furnished by its providers.
   /---\      +---+    +---+      +---+    +---+      /---\
   |C11|------|S13|----|S15|------|S23|----|S25|------|C21|
   \---/      +---+\   +---+      +---+   /+---+      \---/
                    \                    /
                     \                  /
                      \+---+      +---+/   +---+      /---\
                       |S18|------|S24|    |S28|------|C22|
                       +---+      +---+\  /+---+      \---/
                                        \/
                                        /\
   /---\      +---+    +---+      +---+/  \+---+      /---\
   |C12|------|S19|----|S17|------|S29|----|S27|------|C23|
   \---/      +---+    +---+      +---+    +---+      \---/
      Domain 1 TE Topology             Domain 2 TE Topology
           +---+    +---+                  +---+    +---+
      -----|S13|----|S15|----          ----|S23|----|S25|----
           +---+\   +---+                  +---+   /+---+
                 \                                /
                  \                              /
                   \+---+                  +---+/   +---+
                    |S18|----          ----|S24|    |S28|----
                    +---+                  +---+\  /+---+
                                                 \/
                                                 /\
           +---+    +---+                  +---+/  \+---+
      -----|S19|----|S17|----          ----|S29|----|S27|----
           +---+    +---+                  +---+    +---+
          Figure 13: Merging Domain TE Topologies: An Example
 In Figure 13, each of the two providers caters to the client
 (abstract or Native) TE topology, describing the network domain under
 the respective provider's control.  The client, by consulting such
 attributes of the inter-domain TE links as inter-domain plug IDs or
 remote TE node IDs / link IDs (as defined by the TE topology model),
 is able to determine that:
 1.  the two domains are adjacent and are interconnected via three
     inter-domain TE links, and
 2.  each domain is connected to a separate customer site, connecting
     the domain on the left in the figure to customer devices C11 and
     C12, and the domain on the right to customer devices C21, C22,
     and C23.
 Therefore, the client interconnects the open-ended TE links, as shown
 on the upper part of the figure.
 As mentioned previously, one way to interconnect the open-ended
 inter-domain TE links of neighboring domains is to mandate that the
 providers specify a remote node ID / link ID attribute in the
 provided inter-domain TE links.  However, this may prove not to be
 flexible.  For example, the providers may not know the respective
 remote node IDs / link IDs.  More importantly, this option does not
 allow the client to mix and match multiple topologies (more than one
 topology) catered by the same providers (see below).  Another option
 (which is more flexible) for resolving the open-ended inter-domain TE
 links is to annotate them with the inter-domain plug ID attribute.
 The inter-domain plug ID is a network-wide unique number that
 identifies on the network a connection that supports a given inter-
 domain TE link.  Instead of specifying a remote node ID / link ID, an
 inter-domain TE link may provide a non-zero inter-domain plug ID.  It
 is expected that two neighboring domain TE topologies (provided by
 separate providers) will each have at least one open-ended inter-
 domain TE link with an inter-domain plug ID matching an ID provided
 by its neighbor.  For example, the inter-domain TE link originating
 from node S15 of the Domain 1 TE topology (Figure 13) and the inter-
 domain TE link coming from node S23 of the Domain 2 TE topology may
 specify a matching inter-domain plug ID (e.g., 175344).  This allows
 the client to identify adjacent nodes in the separate neighboring TE
 topologies and resolve the inter-domain TE links connecting them,
 regardless of their respective node IDs / link IDs (which, as
 mentioned previously, could be allocated from independent
 namespaces).  Inter-domain plug IDs may be assigned and managed by a
 central network authority.  Alternatively, inter-domain plug IDs
 could be dynamically autodiscovered (e.g., via the Link Management
 Protocol (LMP)).
 Furthermore, the client renames the TE nodes, links, and SRLGs
 offered in the abstract TE topologies by assigning to them IDs
 allocated from a separate namespace managed by the client.  Such
 renaming is necessary, because the two abstract TE topologies may
 have their own namespaces, generally speaking, independent one from
 another; hence, ID overlaps/clashes are possible.  For example, both
 TE topologies have TE nodes named S7, which, after renaming, appear
 in the merged TE topology as S17 and S27, respectively.
 Once the merging process is complete, the client can use the merged
 TE topology for path computations across both domains -- for example,
 to compute a TE path connecting C11 to C23.

4.4. Dealing with Multiple Abstract TE Topologies Provided by the Same

    Provider
 Based on local configuration, templates, and/or policies pushed by
 the client, a given provider may expose more than one abstract TE
 topology to the client.  For example, one abstract TE topology could
 be optimized based on a lowest-cost criterion, while another one
 could be based on best possible delay metrics, while yet another one
 could be based on maximum bandwidth availability for the client
 services.  Furthermore, the client may request all or some providers
 to expose additional abstract TE topologies, possibly of a different
 type and/or optimized differently, as compared to already-provided TE
 topologies.  In any case, the client should be prepared for a
 provider to offer to the client more than one abstract TE topology.
 It should be up to the client (based on the client's local
 configuration and/or policies conveyed to the client by the client's
 clients) to decide how to mix and match multiple abstract TE
 topologies provided by each or some of the providers, as well as how
 to merge them into the client's Native TE topologies.  The client
 also decides how many such merged TE topologies it needs to produce
 and maintain.  For example, in addition to the merged TE topology
 depicted in the upper part of Figure 13, the client may merge the
 abstract TE topologies received from the two providers, as shown in
 Figure 14, into the client's additional Native TE topologies, as
 shown in Figure 15.
      Domain 1 Abstract TE Topology 1  Domain 2 Abstract TE Topology 1
           +---+    +---+                  +---+    +---+
      -----|S13|----|S15|----          ----|S23|----|S25|----
           +---+\   +---+                  +---+   /+---+
                 \                                /
                  \                              /
                   \+---+                  +---+/   +---+
                    |S18|----          ----|S24|    |S28|----
                    +---+                  +---+\  /+---+
                                                 \/
                                                 /\
           +---+    +---+                  +---+/  \+---+
      -----|S19|----|S17|----          ----|S29|----|S27|----
           +---+    +---+                  +---+    +---+
      Domain 1 Abstract TE Topology 2  Domain 2 Abstract TE Topology 2
           +------------+                  +------------+
      -----|            |----          ----|            |----
           |            |                  |            |
           |    AN1     |----          ----|    AN1     |----
           |            |                  |            |
      -----|            |----          ----|            |----
           +------------+                  +------------+
        Figure 14: Merging Domain TE Topologies: Another Example
              Client's Merged TE Topology 2
   /---\      +------------+      +------------+      /---\
   |C11|------|            |------|            |------|C21|
   \---/      |            |      |            |      \---/
              |            |      |            |
              |            |      |            |
              |            |      |            |      /---\
              |    AN11    |------|    AN21    |------|C22|
              |            |      |            |      \---/
              |            |      |            |
              |            |      |            |
   /---\      |            |      |            |      /---\
   |C12|------|            |------|            |------|C23|
   \---/      +------------+      +------------+      \---/
              Client's Merged TE Topology 3
   /---\      +------------+      +---+    +---+      /---\
   |C11|------|            |------|S23|----|S25|------|C21|
   \---/      |            |      +---+   /+---+      \---/
              |            |             /
              |            |            /
              |            |      +---+/   +---+      /---\
              |    AN11    |------|S24|    |S28|------|C22|
              |            |      +---+\  /+---+      \---/
              |            |            \/
              |            |            /\
   /---\      |            |      +---+/  \+---+      /---\
   |C12|------|            |------|S29|----|S27|------|C23|
   \---/      +------------+      +---+    +---+      \---/
       Figure 15: Multiple Native (Merged) Client's TE Topologies
 Note that allowing the client to mix and match multiple TE topologies
 assumes that inter-domain plug IDs (rather than a remote node ID /
 link ID) are used as the option for identifying neighboring domains
 and inter-domain TE link resolution.
 It is important to note that each of the three Native (merged) TE
 topologies could be used by the client for computing TE paths for any
 of the multi-domain services.  The choice of which topology to use
 for a given service depends on the service parameters/requirements,
 the topology's style and optimization criteria, and the level of
 detail.

5. Modeling Considerations

5.1. Network Topology Building Blocks

 The network topology building blocks are discussed in [RFC8345].  The
 TE topology model defined in this document augments and uses the
 "ietf-network-topology" module defined in [RFC8345].
                      +------------------------+
                      | Network Topology Model |
                      | (ietf-network-topology)|
                      +------------------------+
                                   |
                                   |
                                   |
                                   V
                      +------------------------+
                      |       TE Topology      |
                      |         Model          |
                      +------------------------+
            Figure 16: Augmenting the Network Topology Model

5.2. Technology-Agnostic TE Topology Model

 The TE topology model defined in this document is meant to be network
 technology agnostic.  Other technology-specific TE topology models
 can augment and use the building blocks provided by this model, as
 illustrated in Figure 17.
                 +-----------------------------+
                 |      TE Topology Model      |
                 +-----------------------------+
                                |
           +-------------+-------------+-------------+
           |             |             |             |
           V             V             V             V
    +-------------+                            +-------------+
    | Technology- |                            | Technology- |
    |  Specific   |   ......................   |  Specific   |
    | TE Topology |                            | TE Topology |
    |   Model 1   |                            |   Model n   |
    +-------------+                            +-------------+
    Figure 17: Augmenting the Technology-Agnostic TE Topology Model

5.3. Model Structure

 The high-level model structure defined by this document is as shown
 below:
 module: ietf-te-topology
   augment /nw:networks/nw:network/nw:network-types:
     +--rw te-topology!
   augment /nw:networks:
     +--rw te!
        +--rw templates
           +--rw node-template* [name] {template}?
           |  ............
           +--rw link-template* [name] {template}?
              ............
   augment /nw:networks/nw:network:
     +--rw te-topology-identifier
     |  +--rw provider-id?   te-global-id
     |  +--rw client-id?     te-global-id
     |  +--rw topology-id?   te-topology-id
     +--rw te!
        |  ............
   augment /nw:networks/nw:network/nw:node:
     +--rw te-node-id?   te-types:te-node-id
     +--rw te!
        |  ............
        +--rw tunnel-termination-point* [tunnel-tp-id]
           +--rw tunnel-tp-id    binary
           |  ............
           +--rw supporting-tunnel-termination-point*
                   [node-ref tunnel-tp-ref]
              |  ............
   augment /nw:networks/nw:network/nt:link:
     +--rw te!
        |  ..........
   augment /nw:networks/nw:network/nw:node/nt:termination-point:
     +--rw te-tp-id?   te-types:te-tp-id
     +--rw te!
        |  ............

5.4. Topology Identifiers

 The TE topology is uniquely identified by a key that has three
 constituents -- "topology-id", "provider-id", and "client-id".  The
 combination of "provider-id" and "topology-id" uniquely identifies a
 Native TE topology on a given provider.  "client-id" is used only
 when Customized TE topologies come into play; a "client-id" value of
 "0" is used for Native TE topologies.
   augment /nw:networks/nw:network:
     +--rw te-topology-identifier
     |  +--rw provider-id?   te-global-id
     |  +--rw client-id?     te-global-id
     |  +--rw topology-id?   te-topology-id
     +--rw te!
        |  ............

5.5. Generic TE Link Attributes

 The model covers the definitions for generic TE link attributes --
 bandwidth, administrative groups, SRLGs, switching capabilities, TE
 metric extensions, etc.
   +--rw te-link-attributes
      .....................
      +--rw admin-status?                     te-admin-status
      |  .....................
      +--rw link-index?                       uint64
      +--rw administrative-group?             te-types:admin-groups
      +--rw link-protection-type?             enumeration
      +--rw max-link-bandwidth?               te-bandwidth
      +--rw max-resv-link-bandwidth?          te-bandwidth
      +--rw unreserved-bandwidth* [priority]
      |  .....................
      +--rw te-default-metric?                uint32
      |  .....................
      +--rw te-srlgs
      +--rw te-nsrlgs {nsrlg}?        .....................

5.6. Generic TE Node Attributes

 The model covers the definitions for generic TE node attributes.
 The definition of a generic connectivity matrix is shown below:
   +--rw te-node-attributes
      ...........
      +--rw connectivity-matrices
      ...........
      |  +--rw connectivity-matrix* [id]
      |  |  +--rw id            uint32
      |  |  +--rw from
      |  |  |  +--rw tp-ref?        leafref
      |  |  |  +--rw label-restrictions
      |  |  +--rw to
      |  |  |  +--rw tp-ref?        leafref
      |  |  |  +--rw label-restrictions
      |  |  +--rw is-allowed?   boolean
      ...........
      |  |  +--rw underlay! {te-topology-hierarchy}?
      ...........
      |  |  +--rw path-constraints
      ...........
      |  |  +--rw optimizations
      ...........
      |  |  +--ro path-properties
      ...........
 The definition of a TTP Local Link Connectivity List is shown below:
   +--rw tunnel-termination-point* [tunnel-tp-id]
      +--rw tunnel-tp-id               binary
      +--rw admin-status?              te-types:te-admin-status
      +--rw name?                      string
      +--rw switching-capability?      identityref
      +--rw encoding?                  identityref
      +--rw inter-layer-lock-id*       uint32
      +--rw protection-type?           identityref
      +--rw client-layer-adaptation
      ...........
      +--rw local-link-connectivities
      ...........
      |  +--rw local-link-connectivity* [link-tp-ref]
      |     +--rw link-tp-ref                leafref
      |     +--rw label-restrictions
      ...........
      |     +--rw is-allowed?                 boolean
      |     +--rw underlay {te-topology-hierarchy}?
      ...........
      |     +--rw path-constraints
      ...........
      |     +--rw optimizations
      ...........
      |     +--ro path-properties
      ...........
      +--rw supporting-tunnel-termination-point*
              [node-ref tunnel-tp-ref]
         +--rw node-ref         inet:uri
         +--rw tunnel-tp-ref    binary
 The attributes directly under container "connectivity-matrices" are
 the default attributes for all connectivity matrix entries when the
 per-entry corresponding attribute is not specified.  When a per-entry
 attribute is specified, it overrides the corresponding attribute
 directly under the container "connectivity-matrices".  The same rule
 applies to the attributes directly under container
 "local-link-connectivities".
 Each TTP MAY be supported by one or more supporting TTPs.  If the TE
 node hosting the TTP in question refers to a supporting TE node, then
 the supporting TTPs are hosted by the supporting TE node.  If the TE
 node refers to an underlay TE topology, the supporting TTPs are
 hosted by one or more specified TE nodes of the underlay TE topology.

5.7. TED Information Sources

 The model allows each TE topological element to have multiple TE
 information sources (OSPF-TE, ISIS-TE, Border Gateway Protocol - Link
 State (BGP-LS), user-configured, system-processed, other).  Each
 information source is associated with a credibility preference to
 indicate precedence.  In scenarios where a Customized TE topology is
 merged into a client's Native TE topology, the merged topological
 elements would point to the corresponding Customized TE topology as
 its information source.
   augment /nw:networks/nw:network/nw:node:
     +--rw te!
        ...........
        +--ro information-source?            te-info-source
        +--ro information-source-instance?   string
        +--ro information-source-state
        |  +--ro credibility-preference?    uint16
        |  +--ro logical-network-element?   string
        |  +--ro network-instance?          string
        |  +--ro topology
        |     +--ro node-ref?      leafref
        |     +--ro network-ref?   leafref
        +--ro information-source-entry*
        |       [information-source information-source-instance]
        |  +--ro information-source             te-info-source
        |  +--ro information-source-instance    string
              ............
   augment /nw:networks/nw:network/nt:link:
     +--rw te!
        ...........
        +--ro information-source?            te-info-source
        +--ro information-source-instance?   string
        +--ro information-source-state
        |  +--ro credibility-preference?    uint16
        |  +--ro logical-network-element?   string
        |  +--ro network-instance?          string
        |  +--ro topology
        |     +--ro link-ref?      leafref
        |     +--ro network-ref?   leafref
        +--ro information-source-entry*
        |       [information-source information-source-instance]
        |  +--ro information-source                te-info-source
        |  +--ro information-source-instance       string
              ............

5.8. Overlay/Underlay Relationship

 The model captures the overlay and underlay relationship for TE
 nodes/links.  For example, in networks where multiple TE topologies
 are built hierarchically, this model allows the user to start from a
 specific topological element in the topmost topology and traverse all
 the way down to the supporting topological elements in the bottommost
 topology.
 This relationship is captured via the "underlay-topology" field for
 the node and via the "underlay" field for the link.  The use of these
 fields is optional, and this functionality is tagged as a "feature"
 ("te-topology-hierarchy").
   augment /nw:networks/nw:network/nw:node:
     +--rw te-node-id?   te-types:te-node-id
     +--rw te!
        +--rw te-node-template*           leafref {template}?
        +--rw te-node-attributes
        |  +--rw admin-status?            te-types:te-admin-status
        |  |  ....................
        |  +--rw underlay-topology {te-topology-hierarchy}?
        |     +--rw network-ref?   leafref
   augment /nw:networks/nw:network/nt:link:
     +--rw te!
        +--rw te-link-attributes
        |  ....................
        |  +--rw underlay {te-topology-hierarchy}?
        |  |  +--rw enabled?                     boolean
        |  |  +--rw primary-path
        |  |  |  +--rw network-ref?    leafref
        |  |  |     ....................
        |  |  +--rw backup-path* [index]
        |  |  |  +--rw index           uint32
        |  |  |  +--rw network-ref?    leafref
        |  |  |     ....................
        |  |  +--rw protection-type?             identityref
        |  |  +--rw tunnel-termination-points
        |  |  |  +--rw source?        binary
        |  |  |  +--rw destination?   binary
        |  |  +--rw tunnels
        |  |  |  ....................

5.9. Templates

 The data model provides users with the ability to define templates
 and apply them to link and node configurations.  The use of the
 "template" configuration is optional, and this functionality is
 tagged as a "feature" ("template").
   augment /nw:networks/nw:network/nw:node:
     +--rw te-node-id?   te-types:te-node-id
     +--rw te!
        +--rw te-node-template*
        |       -> ../../../../te/templates/node-template/name
        |       {template}?
   augment /nw:networks/nw:network/nt:link:
     +--rw te!
        +--rw te-link-template*
        |       -> ../../../../te/templates/link-template/name
        |       {template}?
   augment /nw:networks:
     +--rw te!
        +--rw templates
           +--rw node-template* [name] {template}?
           |  +--rw name
           |  |       te-types:te-template-name
           |  +--rw priority?                  uint16
           |  +--rw reference-change-policy?   enumeration
           |  +--rw te-node-attributes
              ..........
           +--rw link-template* [name] {template}?
              +--rw name
              |       te-types:te-template-name
              +--rw priority?                  uint16
              +--rw reference-change-policy?   enumeration
              +--rw te-link-attributes
              ..........
 Multiple templates can be specified for a configuration element.
 When two or more templates specify values for the same configuration
 field, the value from the template with the highest priority is used.
 The range of the priority is from 0 to 65535, with a lower number
 indicating a higher priority.  The "reference-change-policy"
 parameter specifies the action that needs to be taken when the
 template changes on a configuration element that has a reference to
 this template.  The choices of action include taking no action,
 rejecting the change to the template, and applying the change to the
 corresponding configuration.

5.10. Scheduling Parameters

 The model allows time-scheduling parameters to be specified for each
 topological element or for the topology as a whole.  These parameters
 allow the provider to present different topological views to the
 client at different time slots.  The use of time-scheduling
 parameters is optional.
 The YANG data model for configuration scheduling is defined in
 [YANG-CFG-SCHED], which allows specifying configuration schedules
 without altering this data model.

5.11. Notifications

 Notifications are a key component of any topology data model.
 [RFC8639] and [RFC8641] define a subscription mechanism and a push
 mechanism for YANG datastores.  These mechanisms currently allow the
 user to:
  • Subscribe to notifications on a per-client basis.
  • Specify subtree filters or XML Path Language (XPath) filters so

that only contents of interest will be sent.

  • Specify either periodic or on-demand notifications.

6. Guidance for Writing Technology-Specific TE Topology Augmentations

 The TE topology model defined in this document is technology
 agnostic, as it defines concepts, abstractions, and attributes that
 are common across multiple network technologies.  It is envisioned
 that this base model will be widely used when defining technology-
 specific TE topology models for various layer networks.  [YANG-WSON],
 [YANG-OTN], and [YANG-L3] are some examples of technology-specific TE
 topology models.  Writers of such models are encouraged to augment
 the basic TE topology model's containers, such as those for TE
 topologies, TE nodes, TE links, Link Termination Points (LTPs),
 Tunnel Termination Points (TTPs), bandwidth, and labels, with the
 layer-specific attributes instead of defining new containers.
 Consider the following technology-specific example-topology model:
 module: example-topology
   augment /nw:networks/nw:network/nw:network-types/tet:te-topology:
     +--rw example-topology!
   augment /nw:networks/nw:network/tet:te:
     +--rw attributes
        +--rw attribute-1?   uint8
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes:
     +--rw attributes
        +--rw attribute-2?   uint8
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices:
     +--rw attributes
        +--rw attribute-3?   uint8
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:connectivity-matrix:
     +--rw attributes
        +--rw attribute-3?   uint8
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point:
     +--rw attributes
        +--rw attribute-4?   uint8
   augment /nw:networks/nw:network/nw:node/nt:termination-point
             /tet:te:
     +--rw attributes
        +--rw attribute-5?   uint8
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:te-link-attributes:
     +--rw attributes
        +--rw attribute-6?   uint8
 The technology-specific TE bandwidth for this example topology can be
 specified using the following augment statements:
   augment /nw:networks/tet:te/tet:templates/tet:link-template
             /tet:te-link-attributes
             /tet:interface-switching-capability/tet:max-lsp-bandwidth
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
   augment /nw:networks/tet:te/tet:templates/tet:link-template
             /tet:te-link-attributes/tet:max-link-bandwidth
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
   augment /nw:networks/tet:te/tet:templates/tet:link-template
             /tet:te-link-attributes/tet:max-resv-link-bandwidth
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
   augment /nw:networks/tet:te/tet:templates/tet:link-template
             /tet:te-link-attributes/tet:unreserved-bandwidth
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:path-constraints/tet:te-bandwidth/tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:path-constraints
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:path-constraints/tet:te-bandwidth/tet:technology:
     +--:(example)
        +--ro example
           +--ro bandwidth-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:path-constraints
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--ro example
           +--ro bandwidth-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point/tet:client-layer-adaptation
             /tet:switching-capability/tet:te-bandwidth
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point
             /tet:local-link-connectivities/tet:path-constraints
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point
             /tet:local-link-connectivities
             /tet:local-link-connectivity/tet:path-constraints
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:te-link-attributes
             /tet:interface-switching-capability/tet:max-lsp-bandwidth
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:te-link-attributes/tet:max-link-bandwidth
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:te-link-attributes/tet:max-resv-link-bandwidth
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:information-source-entry
             /tet:interface-switching-capability/tet:max-lsp-bandwidth
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--ro example
           +--ro bandwidth-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:information-source-entry/tet:max-link-bandwidth
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--ro example
           +--ro bandwidth-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:information-source-entry/tet:max-resv-link-bandwidth
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--ro example
           +--ro bandwidth-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:information-source-entry/tet:unreserved-bandwidth
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--ro example
           +--ro bandwidth-1?   uint32
   augment /nw:networks/nw:network/nw:node/nt:termination-point/tet:te
             /tet:interface-switching-capability/tet:max-lsp-bandwidth
             /tet:te-bandwidth/tet:technology:
     +--:(example)
        +--rw example
           +--rw bandwidth-1?   uint32
 The technology-specific TE label for this example topology can be
 specified using the following augment statements:
   augment /nw:networks/tet:te/tet:templates/tet:link-template
             /tet:te-link-attributes/tet:underlay/tet:primary-path
             /tet:path-element/tet:type/tet:label/tet:label-hop
             /tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/tet:te/tet:templates/tet:link-template
             /tet:te-link-attributes/tet:underlay/tet:backup-path
             /tet:path-element/tet:type/tet:label/tet:label-hop
             /tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/tet:te/tet:templates/tet:link-template
             /tet:te-link-attributes/tet:label-restrictions
             /tet:label-restriction/tet:label-start/tet:te-label
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/tet:te/tet:templates/tet:link-template
             /tet:te-link-attributes/tet:label-restrictions
             /tet:label-restriction/tet:label-end/tet:te-label
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:label-restrictions/tet:label-restriction
             /tet:label-start/tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:label-restrictions/tet:label-restriction
             /tet:label-end/tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:underlay/tet:primary-path/tet:path-element/tet:type
             /tet:label/tet:label-hop/tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:underlay/tet:backup-path/tet:path-element/tet:type
             /tet:label/tet:label-hop/tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:path-properties/tet:path-route-objects
             /tet:path-route-object/tet:type/tet:label/tet:label-hop
             /tet:te-label/tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:from/tet:label-restrictions
             /tet:label-restriction/tet:label-start/tet:te-label
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:from/tet:label-restrictions
             /tet:label-restriction/tet:label-end/tet:te-label
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:to/tet:label-restrictions
             /tet:label-restriction/tet:label-start/tet:te-label
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:to/tet:label-restrictions
             /tet:label-restriction/tet:label-end/tet:te-label
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:underlay/tet:primary-path
             /tet:path-element/tet:type/tet:label/tet:label-hop
             /tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:underlay/tet:backup-path
             /tet:path-element/tet:type/tet:label/tet:label-hop
             /tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:te-node-attributes/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:path-properties
             /tet:path-route-objects/tet:path-route-object/tet:type
             /tet:label/tet:label-hop/tet:te-label/tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:label-restrictions/tet:label-restriction
             /tet:label-start/tet:te-label/tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:label-restrictions/tet:label-restriction
             /tet:label-end/tet:te-label/tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:underlay/tet:primary-path/tet:path-element/tet:type
             /tet:label/tet:label-hop/tet:te-label/tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:underlay/tet:backup-path/tet:path-element/tet:type
             /tet:label/tet:label-hop/tet:te-label/tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:path-properties/tet:path-route-objects
             /tet:path-route-object/tet:type/tet:label/tet:label-hop
             /tet:te-label/tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:from/tet:label-restrictions
             /tet:label-restriction/tet:label-start/tet:te-label
             /tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:from/tet:label-restrictions
             /tet:label-restriction/tet:label-end/tet:te-label
             /tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:to/tet:label-restrictions
             /tet:label-restriction/tet:label-start/tet:te-label
             /tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:to/tet:label-restrictions
             /tet:label-restriction/tet:label-end/tet:te-label
             /tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:underlay/tet:primary-path
             /tet:path-element/tet:type/tet:label/tet:label-hop
             /tet:te-label/tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:underlay/tet:backup-path
             /tet:path-element/tet:type/tet:label/tet:label-hop
             /tet:te-label/tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:information-source-entry/tet:connectivity-matrices
             /tet:connectivity-matrix/tet:path-properties
             /tet:path-route-objects/tet:path-route-object/tet:type
             /tet:label/tet:label-hop/tet:te-label/tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point
             /tet:local-link-connectivities/tet:label-restrictions
             /tet:label-restriction/tet:label-start/tet:te-label
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point
             /tet:local-link-connectivities/tet:label-restrictions
             /tet:label-restriction/tet:label-end/tet:te-label
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point
             /tet:local-link-connectivities/tet:underlay
             /tet:primary-path/tet:path-element/tet:type/tet:label
             /tet:label-hop/tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point
             /tet:local-link-connectivities/tet:underlay
             /tet:backup-path/tet:path-element/tet:type/tet:label
             /tet:label-hop/tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point
             /tet:local-link-connectivities/tet:path-properties
             /tet:path-route-objects/tet:path-route-object/tet:type
             /tet:label/tet:label-hop/tet:te-label/tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point
             /tet:local-link-connectivities
             /tet:local-link-connectivity/tet:label-restrictions
             /tet:label-restriction/tet:label-start/tet:te-label
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point
             /tet:local-link-connectivities
             /tet:local-link-connectivity/tet:label-restrictions
             /tet:label-restriction/tet:label-end/tet:te-label
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point
             /tet:local-link-connectivities
             /tet:local-link-connectivity/tet:underlay
             /tet:primary-path/tet:path-element/tet:type/tet:label
             /tet:label-hop/tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point
             /tet:local-link-connectivities
             /tet:local-link-connectivity/tet:underlay/tet:backup-path
             /tet:path-element/tet:type/tet:label/tet:label-hop
             /tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nw:node/tet:te
             /tet:tunnel-termination-point
             /tet:local-link-connectivities
             /tet:local-link-connectivity/tet:path-properties
             /tet:path-route-objects/tet:path-route-object/tet:type
             /tet:label/tet:label-hop/tet:te-label/tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:te-link-attributes/tet:label-restrictions
             /tet:label-restriction/tet:label-start/tet:te-label
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:te-link-attributes/tet:label-restrictions
             /tet:label-restriction/tet:label-end/tet:te-label
             /tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:te-link-attributes/tet:underlay/tet:primary-path
             /tet:path-element/tet:type/tet:label/tet:label-hop
             /tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:te-link-attributes/tet:underlay/tet:backup-path
             /tet:path-element/tet:type/tet:label/tet:label-hop
             /tet:te-label/tet:technology:
     +--:(example)
        +--rw example
           +--rw label-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:information-source-entry/tet:label-restrictions
             /tet:label-restriction/tet:label-start/tet:te-label
             /tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
   augment /nw:networks/nw:network/nt:link/tet:te
             /tet:information-source-entry/tet:label-restrictions
             /tet:label-restriction/tet:label-end/tet:te-label
             /tet:technology:
     +--:(example)
        +--ro example
           +--ro label-1?   uint32
 The example YANG module that implements the above example topology is
 provided in Appendix C.

7. TE Topology YANG Module

 This module references [RFC1195], [RFC3209], [RFC3272], [RFC3471],
 [RFC3630], [RFC3785], [RFC4201], [RFC4202], [RFC4203], [RFC4206],
 [RFC4872], [RFC5152], [RFC5212], [RFC5305], [RFC5316], [RFC5392],
 [RFC6001], [RFC6241], [RFC6991], [RFC7308], [RFC7471], [RFC7579],
 [RFC7752], [RFC8345], and [RFC8776].
 <CODE BEGINS> file "ietf-te-topology@2020-08-06.yang"
 module ietf-te-topology {
   yang-version 1.1;
   namespace "urn:ietf:params:xml:ns:yang:ietf-te-topology";
   prefix tet;
   import ietf-yang-types {
     prefix yang;
     reference
       "RFC 6991: Common YANG Data Types";
   }
   import ietf-inet-types {
     prefix inet;
     reference
       "RFC 6991: Common YANG Data Types";
   }
   import ietf-te-types {
     prefix te-types;
     reference
       "RFC 8776: Common YANG Data Types for Traffic Engineering";
   }
   import ietf-network {
     prefix nw;
     reference
       "RFC 8345: A YANG Data Model for Network Topologies";
   }
   import ietf-network-topology {
     prefix nt;
     reference
       "RFC 8345: A YANG Data Model for Network Topologies";
   }
   organization
     "IETF Traffic Engineering Architecture and Signaling (TEAS)
      Working Group";
   contact
     "WG Web:   <https://datatracker.ietf.org/wg/teas/>
      WG List:  <mailto:teas@ietf.org>
      Editor:   Xufeng Liu
                <mailto:xufeng.liu.ietf@gmail.com>
      Editor:   Igor Bryskin
                <mailto:i_bryskin@yahoo.com>
      Editor:   Vishnu Pavan Beeram
                <mailto:vbeeram@juniper.net>
      Editor:   Tarek Saad
                <mailto:tsaad@juniper.net>
      Editor:   Himanshu Shah
                <mailto:hshah@ciena.com>
      Editor:   Oscar Gonzalez de Dios
                <mailto:oscar.gonzalezdedios@telefonica.com>";
   description
     "This YANG module defines a TE topology model for representing,
      retrieving, and manipulating technology-agnostic TE topologies.
      Copyright (c) 2020 IETF Trust and the persons identified as
      authors of the code.  All rights reserved.
      Redistribution and use in source and binary forms, with or
      without modification, is permitted pursuant to, and subject to
      the license terms contained in, the Simplified BSD License set
      forth in Section 4.c of the IETF Trust's Legal Provisions
      Relating to IETF Documents
      (https://trustee.ietf.org/license-info).
      This version of this YANG module is part of RFC 8795; see the
      RFC itself for full legal notices.";
   revision 2020-08-06 {
     description
       "Initial revision.";
     reference
       "RFC 8795: YANG Data Model for Traffic Engineering (TE)
        Topologies";
   }
   /*
    * Features
    */
   feature nsrlg {
     description
       "This feature indicates that the system supports NSRLGs
        (Non-Shared Risk Link Groups).";
   }
   feature te-topology-hierarchy {
     description
       "This feature indicates that the system allows an underlay
        and/or overlay TE topology hierarchy.";
   }
   feature template {
     description
       "This feature indicates that the system supports
        template configuration.";
   }
   /*
    * Typedefs
    */
   typedef geographic-coordinate-degree {
     type decimal64 {
       fraction-digits 8;
     }
     description
       "Decimal degree (DD) used to express latitude and longitude
        geographic coordinates.";
   }
   // geographic-coordinate-degree
   typedef te-info-source {
     type enumeration {
       enum unknown {
         description
           "The source is unknown.";
       }
       enum locally-configured {
         description
           "Configured entity.";
       }
       enum ospfv2 {
         description
           "OSPFv2.";
       }
       enum ospfv3 {
         description
           "OSPFv3.";
       }
       enum isis {
         description
           "IS-IS.";
       }
       enum bgp-ls {
         description
           "BGP-LS.";
         reference
           "RFC 7752: North-Bound Distribution of Link-State and
            Traffic Engineering (TE) Information Using BGP";
       }
       enum system-processed {
         description
           "System-processed entity.";
       }
       enum other {
         description
           "Other source.";
       }
     }
     description
       "Describes the type of source that has provided the
        related information, and the source's credibility.";
   }
   // te-info-source
   /*
    * Groupings
    */
   grouping connectivity-matrix-entry-path-attributes {
     description
       "Attributes of a connectivity matrix entry.";
     leaf is-allowed {
       type boolean;
       description
         "'true' - switching is allowed;
          'false' - switching is disallowed.";
     }
     container underlay {
       if-feature "te-topology-hierarchy";
       description
         "Attributes of the TE link underlay.";
       reference
         "RFC 4206: Label Switched Paths (LSP) Hierarchy with
          Generalized Multi-Protocol Label Switching (GMPLS)
          Traffic Engineering (TE)";
       uses te-link-underlay-attributes;
     }
     uses te-types:generic-path-constraints;
     uses te-types:generic-path-optimization;
     uses te-types:generic-path-properties;
   }
   // connectivity-matrix-entry-path-attributes
   grouping geolocation-container {
     description
       "Contains a GPS location.";
     container geolocation {
       config false;
       description
         "Contains a GPS location.";
       leaf altitude {
         type int64;
         units "millimeters";
         description
           "Distance above sea level.";
       }
       leaf latitude {
         type geographic-coordinate-degree {
           range "-90..90";
         }
         description
           "Relative position north or south on the Earth's surface.";
       }
       leaf longitude {
         type geographic-coordinate-degree {
           range "-180..180";
         }
         description
           "Angular distance east or west on the Earth's surface.";
       }
     }
     // geolocation
   }
   // geolocation-container
   grouping information-source-state-attributes {
     description
       "The attributes identifying the source that has provided the
        related information, and the source's credibility.";
     leaf credibility-preference {
       type uint16;
       description
         "The preference value for calculating the Traffic
          Engineering database credibility value used for
          tie-break selection between different information-source
          values.  A higher value is preferable.";
     }
     leaf logical-network-element {
       type string;
       description
         "When applicable, this is the name of a logical network
          element from which the information is learned.";
     }
     leaf network-instance {
       type string;
       description
         "When applicable, this is the name of a network instance
          from which the information is learned.";
     }
   }
   // information-source-state-attributes
   grouping information-source-per-link-attributes {
     description
       "Per-node container of the attributes identifying the source
        that has provided the related information, and the source's
        credibility.";
     leaf information-source {
       type te-info-source;
       config false;
       description
         "Indicates the type of information source.";
     }
     leaf information-source-instance {
       type string;
       config false;
       description
         "The name indicating the instance of the information
          source.";
     }
     container information-source-state {
       config false;
       description
         "Contains state attributes related to the information
          source.";
       uses information-source-state-attributes;
       container topology {
         description
           "When the information is processed by the system,
            the attributes in this container indicate which topology
            is used to generate the result information.";
         uses nt:link-ref;
       }
     }
   }
   // information-source-per-link-attributes
   grouping information-source-per-node-attributes {
     description
       "Per-node container of the attributes identifying the source
        that has provided the related information, and the source's
        credibility.";
     leaf information-source {
       type te-info-source;
       config false;
       description
         "Indicates the type of information source.";
     }
     leaf information-source-instance {
       type string;
       config false;
       description
         "The name indicating the instance of the information
          source.";
     }
     container information-source-state {
       config false;
       description
         "Contains state attributes related to the information
          source.";
       uses information-source-state-attributes;
       container topology {
         description
           "When the information is processed by the system,
            the attributes in this container indicate which topology
            is used to generate the result information.";
         uses nw:node-ref;
       }
     }
   }
   // information-source-per-node-attributes
   grouping interface-switching-capability-list {
     description
       "List of Interface Switching Capability Descriptors (ISCDs).";
     list interface-switching-capability {
       key "switching-capability encoding";
       description
         "List of ISCDs for this link.";
       reference
         "RFC 3471: Generalized Multi-Protocol Label Switching (GMPLS)
          Signaling Functional Description
          RFC 4203: OSPF Extensions in Support of Generalized
          Multi-Protocol Label Switching (GMPLS)";
       leaf switching-capability {
         type identityref {
           base te-types:switching-capabilities;
         }
         description
           "Switching capability for this interface.";
       }
       leaf encoding {
         type identityref {
           base te-types:lsp-encoding-types;
         }
         description
           "Encoding supported by this interface.";
       }
       uses te-link-iscd-attributes;
     }
     // interface-switching-capability
   }
   // interface-switching-capability-list
   grouping statistics-per-link {
     description
       "Statistics attributes per TE link.";
     leaf discontinuity-time {
       type yang:date-and-time;
       description
         "The time of the most recent occasion at which any one or
          more of this interface's counters suffered a
          discontinuity.  If no such discontinuities have occurred
          since the last re-initialization of the local management
          subsystem, then this node contains the time the local
          management subsystem re-initialized itself.";
     }
     /* Administrative attributes */
     leaf disables {
       type yang:counter32;
       description
         "Number of times that a link was disabled.";
     }
     leaf enables {
       type yang:counter32;
       description
         "Number of times that a link was enabled.";
     }
     leaf maintenance-clears {
       type yang:counter32;
       description
         "Number of times that a link was taken out of maintenance.";
     }
     leaf maintenance-sets {
       type yang:counter32;
       description
         "Number of times that a link was put in maintenance.";
     }
     leaf modifies {
       type yang:counter32;
       description
         "Number of times that a link was modified.";
     }
     /* Operational attributes */
     leaf downs {
       type yang:counter32;
       description
         "Number of times that a link was set to an operational state
          of 'down'.";
     }
     leaf ups {
       type yang:counter32;
       description
         "Number of times that a link was set to an operational state
          of 'up'.";
     }
     /* Recovery attributes */
     leaf fault-clears {
       type yang:counter32;
       description
         "Number of times that a link experienced a fault-clear
          event.";
     }
     leaf fault-detects {
       type yang:counter32;
       description
         "Number of times that a link experienced fault detection.";
     }
     leaf protection-switches {
       type yang:counter32;
       description
         "Number of times that a link experienced protection
          switchover.";
     }
     leaf protection-reverts {
       type yang:counter32;
       description
         "Number of times that a link experienced protection
          reversion.";
     }
     leaf restoration-failures {
       type yang:counter32;
       description
         "Number of times that a link experienced restoration
          failure.";
     }
     leaf restoration-starts {
       type yang:counter32;
       description
         "Number of times that a link experienced restoration
          start.";
     }
     leaf restoration-successes {
       type yang:counter32;
       description
         "Number of times that a link experienced restoration
          success.";
     }
     leaf restoration-reversion-failures {
       type yang:counter32;
       description
         "Number of times that a link experienced restoration
          reversion failure.";
     }
     leaf restoration-reversion-starts {
       type yang:counter32;
       description
         "Number of times that a link experienced restoration
          reversion start.";
     }
     leaf restoration-reversion-successes {
       type yang:counter32;
       description
         "Number of times that a link experienced restoration
          reversion success.";
     }
   }
   // statistics-per-link
   grouping statistics-per-node {
     description
       "Statistics attributes per TE node.";
     leaf discontinuity-time {
       type yang:date-and-time;
       description
         "The time of the most recent occasion at which any one or
          more of this interface's counters suffered a
          discontinuity.  If no such discontinuities have occurred
          since the last re-initialization of the local management
          subsystem, then this node contains the time the local
          management subsystem re-initialized itself.";
     }
     container node {
       description
         "Contains statistics attributes at the TE node level.";
       leaf disables {
         type yang:counter32;
         description
           "Number of times that a node was disabled.";
       }
       leaf enables {
         type yang:counter32;
         description
           "Number of times that a node was enabled.";
       }
       leaf maintenance-sets {
         type yang:counter32;
         description
           "Number of times that a node was put in maintenance.";
       }
       leaf maintenance-clears {
         type yang:counter32;
         description
           "Number of times that a node was taken out of
            maintenance.";
       }
       leaf modifies {
         type yang:counter32;
         description
           "Number of times that a node was modified.";
       }
     }
     // node
     container connectivity-matrix-entry {
       description
         "Contains statistics attributes at the level of a
          connectivity matrix entry.";
       leaf creates {
         type yang:counter32;
         description
           "Number of times that a connectivity matrix entry was
            created.";
         reference
           "RFC 6241: Network Configuration Protocol (NETCONF),
                      Section 7.2, 'create' operation";
       }
       leaf deletes {
         type yang:counter32;
         description
           "Number of times that a connectivity matrix entry was
            deleted.";
         reference
           "RFC 6241: Network Configuration Protocol (NETCONF),
                      Section 7.2, 'delete' operation";
       }
       leaf disables {
         type yang:counter32;
         description
           "Number of times that a connectivity matrix entry was
            disabled.";
       }
       leaf enables {
         type yang:counter32;
         description
           "Number of times that a connectivity matrix entry was
            enabled.";
       }
       leaf modifies {
         type yang:counter32;
         description
           "Number of times that a connectivity matrix entry was
            modified.";
       }
     }
     // connectivity-matrix-entry
   }
   // statistics-per-node
   grouping statistics-per-ttp {
     description
       "Statistics attributes per TE TTP (Tunnel Termination Point).";
     leaf discontinuity-time {
       type yang:date-and-time;
       description
         "The time of the most recent occasion at which any one or
          more of this interface's counters suffered a
          discontinuity.  If no such discontinuities have occurred
          since the last re-initialization of the local management
          subsystem, then this node contains the time the local
          management subsystem re-initialized itself.";
     }
     container tunnel-termination-point {
       description
         "Contains statistics attributes at the TE TTP level.";
       /* Administrative attributes */
       leaf disables {
         type yang:counter32;
         description
           "Number of times that a TTP was disabled.";
       }
       leaf enables {
         type yang:counter32;
         description
           "Number of times that a TTP was enabled.";
       }
       leaf maintenance-clears {
         type yang:counter32;
         description
           "Number of times that a TTP was taken out of maintenance.";
       }
       leaf maintenance-sets {
         type yang:counter32;
         description
           "Number of times that a TTP was put in maintenance.";
       }
       leaf modifies {
         type yang:counter32;
         description
           "Number of times that a TTP was modified.";
       }
       /* Operational attributes */
       leaf downs {
         type yang:counter32;
         description
           "Number of times that a TTP was set to an operational state
            of 'down'.";
       }
       leaf ups {
         type yang:counter32;
         description
           "Number of times that a TTP was set to an operational state
            of 'up'.";
       }
       leaf in-service-clears {
         type yang:counter32;
         description
           "Number of times that a TTP was taken out of service
            (TE tunnel was released).";
       }
       leaf in-service-sets {
         type yang:counter32;
         description
           "Number of times that a TTP was put in service by a TE
            tunnel (TE tunnel was set up).";
       }
     }
     // tunnel-termination-point
     container local-link-connectivity {
       description
         "Contains statistics attributes at the TE LLCL (Local Link
          Connectivity List) level.";
       leaf creates {
         type yang:counter32;
         description
           "Number of times that an LLCL entry was created.";
         reference
           "RFC 6241: Network Configuration Protocol (NETCONF),
                      Section 7.2, 'create' operation";
       }
       leaf deletes {
         type yang:counter32;
         description
           "Number of times that an LLCL entry was deleted.";
         reference
           "RFC 6241: Network Configuration Protocol (NETCONF),
                      Section 7.2, 'delete' operation";
       }
       leaf disables {
         type yang:counter32;
         description
           "Number of times that an LLCL entry was disabled.";
       }
       leaf enables {
         type yang:counter32;
         description
           "Number of times that an LLCL entry was enabled.";
       }
       leaf modifies {
         type yang:counter32;
         description
           "Number of times that an LLCL entry was modified.";
       }
     }
     // local-link-connectivity
   }
   // statistics-per-ttp
   grouping te-link-augment {
     description
       "Augmentation for a TE link.";
     uses te-link-config;
     uses te-link-state-derived;
     container statistics {
       config false;
       description
         "Statistics data.";
       uses statistics-per-link;
     }
   }
   // te-link-augment
   grouping te-link-config {
     description
       "TE link configuration grouping.";
     choice bundle-stack-level {
       description
         "The TE link can be partitioned into bundled links or
          component links.";
       case bundle {
         container bundled-links {
           description
             "A set of bundled links.";
           reference
             "RFC 4201: Link Bundling in MPLS Traffic
              Engineering (TE)";
           list bundled-link {
             key "sequence";
             description
               "Specifies a bundled interface that is
                further partitioned.";
             leaf sequence {
               type uint32;
               description
                 "Identifies the sequence in the bundle.";
             }
           }
         }
       }
       case component {
         container component-links {
           description
             "A set of component links.";
           list component-link {
             key "sequence";
             description
               "Specifies a component interface that is
                sufficient to unambiguously identify the
                appropriate resources.";
             leaf sequence {
               type uint32;
               description
                 "Identifies the sequence in the bundle.";
             }
             leaf src-interface-ref {
               type string;
               description
                 "Reference to a component link interface on the
                  source node.";
             }
             leaf des-interface-ref {
               type string;
               description
                 "Reference to a component link interface on the
                  destination node.";
             }
           }
         }
       }
     }
     // bundle-stack-level
     leaf-list te-link-template {
       if-feature "template";
       type leafref {
         path "../../../../te/templates/link-template/name";
       }
       description
         "The reference to a TE link template.";
     }
     uses te-link-config-attributes;
   }
   // te-link-config
   grouping te-link-config-attributes {
     description
       "Link configuration attributes in a TE topology.";
     container te-link-attributes {
       description
         "Link attributes in a TE topology.";
       leaf access-type {
         type te-types:te-link-access-type;
         description
           "Link access type, which can be point-to-point or
            multi-access.";
       }
       container external-domain {
         description
           "For an inter-domain link, specifies the attributes of
            the remote end of the link, to facilitate the signaling at
            the local end.";
         uses nw:network-ref;
         leaf remote-te-node-id {
           type te-types:te-node-id;
           description
             "Remote TE node identifier, used together with
              'remote-te-link-tp-id' to identify the remote Link
              Termination Point (LTP) in a different domain.";
         }
         leaf remote-te-link-tp-id {
           type te-types:te-tp-id;
           description
             "Remote TE LTP identifier, used together with
              'remote-te-node-id' to identify the remote LTP in a
              different domain.";
         }
       }
       leaf is-abstract {
         type empty;
         description
           "Present if the link is abstract.";
       }
       leaf name {
         type string;
         description
           "Link name.";
       }
       container underlay {
         if-feature "te-topology-hierarchy";
         description
           "Attributes of the TE link underlay.";
         reference
           "RFC 4206: Label Switched Paths (LSP) Hierarchy with
            Generalized Multi-Protocol Label Switching (GMPLS)
            Traffic Engineering (TE)";
         uses te-link-underlay-attributes;
       }
       leaf admin-status {
         type te-types:te-admin-status;
         description
           "The administrative state of the link.";
       }
       uses te-link-info-attributes;
     }
     // te-link-attributes
   }
   // te-link-config-attributes
   grouping te-link-info-attributes {
     description
       "Advertised TE information attributes.";
     leaf link-index {
       type uint64;
       description
         "The link identifier.  If OSPF is used, this object
          represents an ospfLsdbID.  If IS-IS is used, this object
          represents an isisLSPID.  If a locally configured link is
          used, this object represents a unique value, which is
          locally defined in a router.";
     }
     leaf administrative-group {
       type te-types:admin-groups;
       description
         "Administrative group or color of the link.
          This attribute covers both administrative groups (defined
          in RFCs 3630 and 5305) and Extended Administrative Groups
          (defined in RFC 7308).";
       reference
         "RFC 3630: Traffic Engineering (TE) Extensions to OSPF
          Version 2
          RFC 5305: IS-IS Extensions for Traffic Engineering
          RFC 7308: Extended Administrative Groups in MPLS Traffic
          Engineering (MPLS-TE)";
     }
     uses interface-switching-capability-list;
     uses te-types:label-set-info;
     leaf link-protection-type {
       type identityref {
         base te-types:link-protection-type;
       }
       description
         "Link Protection Type desired for this link.";
       reference
         "RFC 4202: Routing Extensions in Support of
          Generalized Multi-Protocol Label Switching (GMPLS)";
     }
     container max-link-bandwidth {
       uses te-types:te-bandwidth;
       description
         "Maximum bandwidth that can be seen on this link in this
          direction.  Units are in bytes per second.";
       reference
         "RFC 3630: Traffic Engineering (TE) Extensions to OSPF
          Version 2
          RFC 5305: IS-IS Extensions for Traffic Engineering";
     }
     container max-resv-link-bandwidth {
       uses te-types:te-bandwidth;
       description
         "Maximum amount of bandwidth that can be reserved in this
          direction in this link.  Units are in bytes per second.";
       reference
         "RFC 3630: Traffic Engineering (TE) Extensions to OSPF
          Version 2
          RFC 5305: IS-IS Extensions for Traffic Engineering";
     }
     list unreserved-bandwidth {
       key "priority";
       max-elements 8;
       description
         "Unreserved bandwidth for priority levels 0-7.  Units are in
          bytes per second.";
       reference
         "RFC 3630: Traffic Engineering (TE) Extensions to OSPF
          Version 2
          RFC 5305: IS-IS Extensions for Traffic Engineering";
       leaf priority {
         type uint8 {
           range "0..7";
         }
         description
           "Priority.";
       }
       uses te-types:te-bandwidth;
     }
     leaf te-default-metric {
       type uint32;
       description
         "Traffic Engineering metric.";
       reference
         "RFC 3630: Traffic Engineering (TE) Extensions to OSPF
          Version 2
          RFC 5305: IS-IS Extensions for Traffic Engineering";
     }
     leaf te-delay-metric {
       type uint32;
       description
         "Traffic Engineering delay metric.";
       reference
         "RFC 7471: OSPF Traffic Engineering (TE) Metric Extensions";
     }
     leaf te-igp-metric {
       type uint32;
       description
         "IGP metric used for Traffic Engineering.";
       reference
         "RFC 3785: Use of Interior Gateway Protocol (IGP) Metric as a
          second MPLS Traffic Engineering (TE) Metric";
     }
     container te-srlgs {
       description
         "Contains a list of SRLGs.";
       leaf-list value {
         type te-types:srlg;
         description
           "SRLG value.";
         reference
           "RFC 4202: Routing Extensions in Support of
            Generalized Multi-Protocol Label Switching (GMPLS)";
       }
     }
     container te-nsrlgs {
       if-feature "nsrlg";
       description
         "Contains a list of NSRLGs (Non-Shared Risk Link Groups).
          When an abstract TE link is configured, this list specifies
          the request that underlay TE paths need to be mutually
          disjoint with other TE links in the same groups.";
       leaf-list id {
         type uint32;
         description
           "NSRLG ID, uniquely configured within a topology.";
         reference
           "RFC 4872: RSVP-TE Extensions in Support of End-to-End
            Generalized Multi-Protocol Label Switching (GMPLS)
            Recovery";
       }
     }
   }
   // te-link-info-attributes
   grouping te-link-iscd-attributes {
     description
       "TE link ISCD attributes.";
     reference
       "RFC 4203: OSPF Extensions in Support of Generalized
        Multi-Protocol Label Switching (GMPLS), Section 1.4";
     list max-lsp-bandwidth {
       key "priority";
       max-elements 8;
       description
         "Maximum Label Switched Path (LSP) bandwidth at
          priorities 0-7.";
       leaf priority {
         type uint8 {
           range "0..7";
         }
         description
           "Priority.";
       }
       uses te-types:te-bandwidth;
     }
   }
   // te-link-iscd-attributes
   grouping te-link-state-derived {
     description
       "Link state attributes in a TE topology.";
     leaf oper-status {
       type te-types:te-oper-status;
       config false;
       description
         "The current operational state of the link.";
     }
     leaf is-transitional {
       type empty;
       config false;
       description
         "Present if the link is transitional; used as an
          alternative approach in lieu of 'inter-layer-lock-id'
          for path computation in a TE topology covering multiple
          layers or multiple regions.";
       reference
         "RFC 5212: Requirements for GMPLS-Based Multi-Region and
          Multi-Layer Networks (MRN/MLN)
          RFC 6001: Generalized MPLS (GMPLS) Protocol Extensions
          for Multi-Layer and Multi-Region Networks (MLN/MRN)";
     }
     uses information-source-per-link-attributes;
     list information-source-entry {
       key "information-source information-source-instance";
       config false;
       description
         "A list of information sources learned, including the source
          that is used.";
       uses information-source-per-link-attributes;
       uses te-link-info-attributes;
     }
     container recovery {
       config false;
       description
         "Status of the recovery process.";
       leaf restoration-status {
         type te-types:te-recovery-status;
         description
           "Restoration status.";
       }
       leaf protection-status {
         type te-types:te-recovery-status;
         description
           "Protection status.";
       }
     }
     container underlay {
       if-feature "te-topology-hierarchy";
       config false;
       description
         "State attributes for the TE link underlay.";
       leaf dynamic {
         type boolean;
         description
           "'true' if the underlay is dynamically created.";
       }
       leaf committed {
         type boolean;
         description
           "'true' if the underlay is committed.";
       }
     }
   }
   // te-link-state-derived
   grouping te-link-underlay-attributes {
     description
       "Attributes for the TE link underlay.";
     reference
       "RFC 4206: Label Switched Paths (LSP) Hierarchy with
        Generalized Multi-Protocol Label Switching (GMPLS)
        Traffic Engineering (TE)";
     leaf enabled {
       type boolean;
       description
         "'true' if the underlay is enabled.
          'false' if the underlay is disabled.";
     }
     container primary-path {
       description
         "The service path on the underlay topology that
          supports this link.";
       uses nw:network-ref;
       list path-element {
         key "path-element-id";
         description
           "A list of path elements describing the service path.";
         leaf path-element-id {
           type uint32;
           description
             "To identify the element in a path.";
         }
         uses te-path-element;
       }
     }
     // primary-path
     list backup-path {
       key "index";
       description
         "A list of backup service paths on the underlay topology that
          protect the underlay primary path.  If the primary path is
          not protected, the list contains zero elements.  If the
          primary path is protected, the list contains one or more
          elements.";
       leaf index {
         type uint32;
         description
           "A sequence number to identify a backup path.";
       }
       uses nw:network-ref;
       list path-element {
         key "path-element-id";
         description
           "A list of path elements describing the backup service
            path.";
         leaf path-element-id {
           type uint32;
           description
             "To identify the element in a path.";
         }
         uses te-path-element;
       }
     }
     // backup-path
     leaf protection-type {
       type identityref {
         base te-types:lsp-protection-type;
       }
       description
         "Underlay protection type desired for this link.";
     }
     container tunnel-termination-points {
       description
         "Underlay TTPs desired for this link.";
       leaf source {
         type binary;
         description
           "Source TTP identifier.";
       }
       leaf destination {
         type binary;
         description
           "Destination TTP identifier.";
       }
     }
     container tunnels {
       description
         "Underlay TE tunnels supporting this TE link.";
       leaf sharing {
         type boolean;
         default "true";
         description
           "'true' if the underlay tunnel can be shared with other
            TE links;
            'false' if the underlay tunnel is dedicated to this
            TE link.
            This leaf is the default option for all TE tunnels
            and may be overridden by the per-TE-tunnel value.";
       }
       list tunnel {
         key "tunnel-name";
         description
           "Zero, one, or more underlay TE tunnels that support this
            TE link.";
         leaf tunnel-name {
           type string;
           description
             "A tunnel name uniquely identifies an underlay TE tunnel,
              used together with the 'source-node' value for this
              link.";
           reference
             "RFC 3209: RSVP-TE: Extensions to RSVP for LSP Tunnels";
         }
         leaf sharing {
           type boolean;
           description
             "'true' if the underlay tunnel can be shared with other
              TE links;
              'false' if the underlay tunnel is dedicated to this
              TE link.";
         }
       }
       // tunnel
     }
     // tunnels
   }
   // te-link-underlay-attributes
   grouping te-node-augment {
     description
       "Augmentation for a TE node.";
     uses te-node-config;
     uses te-node-state-derived;
     container statistics {
       config false;
       description
         "Statistics data.";
       uses statistics-per-node;
     }
     list tunnel-termination-point {
       key "tunnel-tp-id";
       description
         "A termination point can terminate a tunnel.";
       leaf tunnel-tp-id {
         type binary;
         description
           "TTP identifier.";
       }
       uses te-node-tunnel-termination-point-config;
       leaf oper-status {
         type te-types:te-oper-status;
         config false;
         description
           "The current operational state of the TTP.";
       }
       uses geolocation-container;
       container statistics {
         config false;
         description
           "Statistics data.";
         uses statistics-per-ttp;
       }
       // Relationship to other TTPs
       list supporting-tunnel-termination-point {
         key "node-ref tunnel-tp-ref";
         description
           "Identifies the TTPs on which this TTP depends.";
         leaf node-ref {
           type inet:uri;
           description
             "This leaf identifies the node in which the supporting
              TTP is present.
              This node is either the supporting node or a node in
              an underlay topology.";
         }
         leaf tunnel-tp-ref {
           type binary;
           description
             "Reference to a TTP that is in either the supporting node
              or a node in an underlay topology.";
         }
       }
       // supporting-tunnel-termination-point
     }
     // tunnel-termination-point
   }
   // te-node-augment
   grouping te-node-config {
     description
       "TE node configuration grouping.";
     leaf-list te-node-template {
       if-feature "template";
       type leafref {
         path "../../../../te/templates/node-template/name";
       }
       description
         "The reference to a TE node template.";
     }
     uses te-node-config-attributes;
   }
   // te-node-config
   grouping te-node-config-attributes {
     description
       "Configuration node attributes in a TE topology.";
     container te-node-attributes {
       description
         "Contains node attributes in a TE topology.";
       leaf admin-status {
         type te-types:te-admin-status;
         description
           "The administrative state of the link.";
       }
       uses te-node-connectivity-matrices;
       uses te-node-info-attributes;
     }
   }
   // te-node-config-attributes
   grouping te-node-config-attributes-template {
     description
       "Configuration node attributes for a template in a TE
        topology.";
     container te-node-attributes {
       description
         "Contains node attributes in a TE topology.";
       leaf admin-status {
         type te-types:te-admin-status;
         description
           "The administrative state of the link.";
       }
       uses te-node-info-attributes;
     }
   }
   // te-node-config-attributes-template
   grouping te-node-connectivity-matrices {
     description
       "Connectivity matrix on a TE node.";
     container connectivity-matrices {
       description
         "Contains a connectivity matrix on a TE node.";
       leaf number-of-entries {
         type uint16;
         description
           "The number of connectivity matrix entries.
            If this number is specified in the configuration request,
            the number is the requested number of entries, which may
            not all be listed in the list;
            if this number is reported in the state data,
            the number is the current number of operational entries.";
       }
       uses te-types:label-set-info;
       uses connectivity-matrix-entry-path-attributes;
       list connectivity-matrix {
         key "id";
         description
           "Represents a node's switching limitations, i.e.,
            limitations in the interconnecting network TE links
            across the node.";
         reference
           "RFC 7579: General Network Element Constraint Encoding
            for GMPLS-Controlled Networks";
         leaf id {
           type uint32;
           description
             "Identifies the connectivity matrix entry.";
         }
       }
       // connectivity-matrix
     }
     // connectivity-matrices
   }
   // te-node-connectivity-matrices
   grouping te-node-connectivity-matrix-attributes {
     description
       "Termination point references of a connectivity matrix entry.";
     container from {
       description
         "Reference to a source LTP.";
       leaf tp-ref {
         type leafref {
           path "../../../../../../nt:termination-point/nt:tp-id";
         }
         description
           "Relative reference to a termination point.";
       }
       uses te-types:label-set-info;
     }
     container to {
       description
         "Reference to a destination LTP.";
       leaf tp-ref {
         type leafref {
           path "../../../../../../nt:termination-point/nt:tp-id";
         }
         description
           "Relative reference to a termination point.";
       }
       uses te-types:label-set-info;
     }
     uses connectivity-matrix-entry-path-attributes;
   }
   // te-node-connectivity-matrix-attributes
   grouping te-node-info-attributes {
     description
       "Advertised TE information attributes.";
     leaf domain-id {
       type uint32;
       description
         "Identifies the domain to which this node belongs.
          This attribute is used to support inter-domain links.";
       reference
         "RFC 5152: A Per-Domain Path Computation Method for
          Establishing Inter-Domain Traffic Engineering (TE)
          Label Switched Paths (LSPs)
          RFC 5316: ISIS Extensions in Support of Inter-Autonomous
          System (AS) MPLS and GMPLS Traffic Engineering
          RFC 5392: OSPF Extensions in Support of Inter-Autonomous
          System (AS) MPLS and GMPLS Traffic Engineering";
     }
     leaf is-abstract {
       type empty;
       description
         "Present if the node is abstract; not present if the node
          is actual.";
     }
     leaf name {
       type string;
       description
         "Node name.";
     }
     leaf-list signaling-address {
       type inet:ip-address;
       description
         "The node's signaling address.";
     }
     container underlay-topology {
       if-feature "te-topology-hierarchy";
       description
         "When an abstract node encapsulates a topology, the
          attributes in this container point to said topology.";
       uses nw:network-ref;
     }
   }
   // te-node-info-attributes
   grouping te-node-state-derived {
     description
       "Node state attributes in a TE topology.";
     leaf oper-status {
       type te-types:te-oper-status;
       config false;
       description
         "The current operational state of the node.";
     }
     uses geolocation-container;
     leaf is-multi-access-dr {
       type empty;
       config false;
       description
         "The presence of this attribute indicates that this TE node
          is a pseudonode elected as a designated router.";
       reference
         "RFC 1195: Use of OSI IS-IS for Routing in TCP/IP and Dual
          Environments
          RFC 3630: Traffic Engineering (TE) Extensions to OSPF
          Version 2";
     }
     uses information-source-per-node-attributes;
     list information-source-entry {
       key "information-source information-source-instance";
       config false;
       description
         "A list of information sources learned, including the source
          that is used.";
       uses information-source-per-node-attributes;
       uses te-node-connectivity-matrices;
       uses te-node-info-attributes;
     }
   }
   // te-node-state-derived
   grouping te-node-tunnel-termination-point-config {
     description
       "Termination capability of a TTP on a TE node.";
     uses te-node-tunnel-termination-point-config-attributes;
     container local-link-connectivities {
       description
         "Contains an LLCL for a TTP on a TE node.";
       leaf number-of-entries {
         type uint16;
         description
           "The number of LLCL entries.
            If this number is specified in the configuration request,
            the number is the requested number of entries, which may
            not all be listed in the list;
            if this number is reported in the state data,
            the number is the current number of operational entries.";
       }
       uses te-types:label-set-info;
       uses connectivity-matrix-entry-path-attributes;
     }
   }
   // te-node-tunnel-termination-point-config
   grouping te-node-tunnel-termination-point-config-attributes {
     description
       "Configuration attributes of a TTP on a TE node.";
     leaf admin-status {
       type te-types:te-admin-status;
       description
         "The administrative state of the TTP.";
     }
     leaf name {
       type string;
       description
         "A descriptive name for the TTP.";
     }
     leaf switching-capability {
       type identityref {
         base te-types:switching-capabilities;
       }
       description
         "Switching capability for this interface.";
     }
     leaf encoding {
       type identityref {
         base te-types:lsp-encoding-types;
       }
       description
         "Encoding supported by this interface.";
     }
     leaf-list inter-layer-lock-id {
       type uint32;
       description
         "Inter-layer lock ID, used for path computation in a TE
          topology covering multiple layers or multiple regions.";
       reference
         "RFC 5212: Requirements for GMPLS-Based Multi-Region and
          Multi-Layer Networks (MRN/MLN)
          RFC 6001: Generalized MPLS (GMPLS) Protocol Extensions
          for Multi-Layer and Multi-Region Networks (MLN/MRN)";
     }
     leaf protection-type {
       type identityref {
         base te-types:lsp-protection-type;
       }
       description
         "The protection type that this TTP is capable of.";
     }
     container client-layer-adaptation {
       description
         "Contains capability information to support a client-layer
          adaptation in a multi-layer topology.";
       list switching-capability {
         key "switching-capability encoding";
         description
           "List of supported switching capabilities.";
         reference
           "RFC 4202: Routing Extensions in Support of
            Generalized Multi-Protocol Label Switching (GMPLS)
            RFC 6001: Generalized MPLS (GMPLS) Protocol Extensions
            for Multi-Layer and Multi-Region Networks (MLN/MRN)";
         leaf switching-capability {
           type identityref {
             base te-types:switching-capabilities;
           }
           description
             "Switching capability for the client-layer adaptation.";
         }
         leaf encoding {
           type identityref {
             base te-types:lsp-encoding-types;
           }
           description
             "Encoding supported by the client-layer adaptation.";
         }
         uses te-types:te-bandwidth;
       }
     }
   }
   // te-node-tunnel-termination-point-config-attributes
   grouping te-node-tunnel-termination-point-llc-list {
     description
       "LLCL of a TTP on a TE node.";
     list local-link-connectivity {
       key "link-tp-ref";
       description
         "The termination capabilities between the TTP and the LTP.
          This capability information can be used to compute
          the tunnel path.
          The Interface Adjustment Capability Descriptors (IACDs)
          (defined in RFC 6001) on each LTP can be derived from
          this list.";
       reference
         "RFC 6001: Generalized MPLS (GMPLS) Protocol Extensions
          for Multi-Layer and Multi-Region Networks (MLN/MRN)";
       leaf link-tp-ref {
         type leafref {
           path "../../../../../nt:termination-point/nt:tp-id";
         }
         description
           "LTP.";
       }
       uses te-types:label-set-info;
       uses connectivity-matrix-entry-path-attributes;
     }
   }
   // te-node-tunnel-termination-point-llc-list
   grouping te-path-element {
     description
       "A group of attributes defining an element in a TE path,
        such as a TE node, TE link, TE atomic resource, or label.";
     uses te-types:explicit-route-hop;
   }
   // te-path-element
   grouping te-termination-point-augment {
     description
       "Augmentation for a TE termination point.";
     leaf te-tp-id {
       type te-types:te-tp-id;
       description
         "An identifier that uniquely identifies a TE termination
          point.";
     }
     container te {
       must '../te-tp-id';
       presence "TE support";
       description
         "Indicates TE support.";
       uses te-termination-point-config;
       leaf oper-status {
         type te-types:te-oper-status;
         config false;
         description
           "The current operational state of the LTP.";
       }
       uses geolocation-container;
     }
   }
   // te-termination-point-augment
   grouping te-termination-point-config {
     description
       "TE termination point configuration grouping.";
     leaf admin-status {
       type te-types:te-admin-status;
       description
         "The administrative state of the LTP.";
     }
     leaf name {
       type string;
       description
         "A descriptive name for the LTP.";
     }
     uses interface-switching-capability-list;
     leaf inter-domain-plug-id {
       type binary;
       description
         "A network-wide unique number that identifies on the
          network a connection that supports a given inter-domain
          TE link.  This is a more flexible alternative to specifying
          'remote-te-node-id' and 'remote-te-link-tp-id' on a TE link
          when the provider either does not know 'remote-te-node-id'
          and 'remote-te-link-tp-id' or needs to give the client the
          flexibility to mix and match multiple topologies.";
     }
     leaf-list inter-layer-lock-id {
       type uint32;
       description
         "Inter-layer lock ID, used for path computation in a TE
          topology covering multiple layers or multiple regions.";
       reference
         "RFC 5212: Requirements for GMPLS-Based Multi-Region and
          Multi-Layer Networks (MRN/MLN)
          RFC 6001: Generalized MPLS (GMPLS) Protocol Extensions
          for Multi-Layer and Multi-Region Networks (MLN/MRN)";
     }
   }
   // te-termination-point-config
   grouping te-topologies-augment {
     description
       "Augmentation for TE topologies.";
     container te {
       presence "TE support";
       description
         "Indicates TE support.";
       container templates {
         description
           "Configuration parameters for templates used for a TE
            topology.";
         list node-template {
           if-feature "template";
           key "name";
           leaf name {
             type te-types:te-template-name;
             description
               "The name to identify a TE node template.";
           }
           description
             "The list of TE node templates used to define sharable
              and reusable TE node attributes.";
           uses template-attributes;
           uses te-node-config-attributes-template;
         }
         // node-template
         list link-template {
           if-feature "template";
           key "name";
           leaf name {
             type te-types:te-template-name;
             description
               "The name to identify a TE link template.";
           }
           description
             "The list of TE link templates used to define sharable
              and reusable TE link attributes.";
           uses template-attributes;
           uses te-link-config-attributes;
         }
         // link-template
       }
       // templates
     }
     // te
   }
   // te-topologies-augment
   grouping te-topology-augment {
     description
       "Augmentation for a TE topology.";
     uses te-types:te-topology-identifier;
     container te {
       must '../te-topology-identifier/provider-id'
          + ' and ../te-topology-identifier/client-id'
          + ' and ../te-topology-identifier/topology-id';
       presence "TE support";
       description
         "Indicates TE support.";
       uses te-topology-config;
       uses geolocation-container;
     }
   }
   // te-topology-augment
   grouping te-topology-config {
     description
       "TE topology configuration grouping.";
     leaf name {
       type string;
       description
         "Name of the TE topology.  This attribute is optional and can
          be specified by the operator to describe the TE topology,
          which can be useful when 'network-id' (RFC 8345) is not
          descriptive and not modifiable because of being generated
          by the system.";
       reference
         "RFC 8345: A YANG Data Model for Network Topologies";
     }
     leaf preference {
       type uint8 {
         range "1..255";
       }
       description
         "Specifies a preference for this topology.  A lower number
          indicates a higher preference.";
     }
     leaf optimization-criterion {
       type identityref {
         base te-types:objective-function-type;
       }
       description
         "Optimization criterion applied to this topology.";
       reference
         "RFC 3272: Overview and Principles of Internet Traffic
          Engineering";
     }
     list nsrlg {
       if-feature "nsrlg";
       key "id";
       description
         "List of NSRLGs (Non-Shared Risk Link Groups).";
       reference
         "RFC 4872: RSVP-TE Extensions in Support of End-to-End
          Generalized Multi-Protocol Label Switching (GMPLS)
          Recovery";
       leaf id {
         type uint32;
         description
           "Identifies the NSRLG entry.";
       }
       leaf disjointness {
         type te-types:te-path-disjointness;
         description
           "The type of resource disjointness.";
       }
     }
     // nsrlg
   }
   // te-topology-config
   grouping template-attributes {
     description
       "Common attributes for all templates.";
     leaf priority {
       type uint16;
       description
         "The preference value for resolving conflicts between
          different templates.  When two or more templates specify
          values for one configuration attribute, the value from the
          template with the highest priority is used.
          A lower number indicates a higher priority.  The highest
          priority is 0.";
     }
     leaf reference-change-policy {
       type enumeration {
         enum no-action {
           description
             "When an attribute changes in this template, the
              configuration node referring to this template does
              not take any action.";
         }
         enum not-allowed {
           description
             "When any configuration object has a reference to this
              template, changing this template is not allowed.";
         }
         enum cascade {
           description
             "When an attribute changes in this template, the
              configuration object referring to this template applies
              the new attribute value to the corresponding
              configuration.";
         }
       }
       description
         "This attribute specifies the action taken for a
          configuration node that has a reference to this template.";
     }
   }
   // template-attributes
   /*
    * Data nodes
    */
   augment "/nw:networks/nw:network/nw:network-types" {
     description
       "Introduces a new network type for a TE topology.";
     container te-topology {
       presence "Indicates a TE topology";
       description
         "Its presence identifies the TE topology type.";
     }
   }
   augment "/nw:networks" {
     description
       "Augmentation parameters for TE topologies.";
     uses te-topologies-augment;
   }
   augment "/nw:networks/nw:network" {
     when 'nw:network-types/tet:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Configuration parameters for a TE topology.";
     uses te-topology-augment;
   }
   augment "/nw:networks/nw:network/nw:node" {
     when '../nw:network-types/tet:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Configuration parameters for TE at the node level.";
     leaf te-node-id {
       type te-types:te-node-id;
       description
         "The identifier of a node in the TE topology.
          A node is specific to a topology to which it belongs.";
     }
     container te {
       must '../te-node-id' {
         description
           "'te-node-id' is mandatory.";
       }
       must 'count(../nw:supporting-node)<=1' {
         description
           "For a node in a TE topology, there cannot be more
            than one supporting node.  If multiple nodes are
            abstracted, the 'underlay-topology' field is used.";
       }
       presence "TE support";
       description
         "Indicates TE support.";
       uses te-node-augment;
     }
   }
   augment "/nw:networks/nw:network/nt:link" {
     when '../nw:network-types/tet:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Configuration parameters for TE at the link level.";
     container te {
       must 'count(../nt:supporting-link)<=1' {
         description
           "For a link in a TE topology, there cannot be more
            than one supporting link.  If one or more link paths are
            abstracted, the underlay is used.";
       }
       presence "TE support";
       description
         "Indicates TE support.";
       uses te-link-augment;
     }
   }
   augment "/nw:networks/nw:network/nw:node/"
         + "nt:termination-point" {
     when '../../nw:network-types/tet:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Configuration parameters for TE at the termination point
        level.";
     uses te-termination-point-augment;
   }
   augment "/nw:networks/nw:network/nt:link/te/bundle-stack-level/"
         + "bundle/bundled-links/bundled-link" {
     when '../../../../nw:network-types/tet:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Augmentation for a TE bundled link.";
     leaf src-tp-ref {
       type leafref {
         path "../../../../../nw:node[nw:node-id = "
            + "current()/../../../../nt:source/"
            + "nt:source-node]/"
            + "nt:termination-point/nt:tp-id";
         require-instance true;
       }
       description
         "Reference to another TE termination point on the
          same source node.";
     }
     leaf des-tp-ref {
       type leafref {
         path "../../../../../nw:node[nw:node-id = "
            + "current()/../../../../nt:destination/"
            + "nt:dest-node]/"
            + "nt:termination-point/nt:tp-id";
         require-instance true;
       }
       description
         "Reference to another TE termination point on the
          same destination node.";
     }
   }
   augment "/nw:networks/nw:network/nw:node/te/"
         + "information-source-entry/connectivity-matrices/"
         + "connectivity-matrix" {
     when '../../../../../nw:network-types/tet:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Augmentation for the TE node connectivity matrix.";
     uses te-node-connectivity-matrix-attributes;
   }
   augment "/nw:networks/nw:network/nw:node/te/te-node-attributes/"
         + "connectivity-matrices/connectivity-matrix" {
     when '../../../../../nw:network-types/tet:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Augmentation for the TE node connectivity matrix.";
     uses te-node-connectivity-matrix-attributes;
   }
   augment "/nw:networks/nw:network/nw:node/te/"
         + "tunnel-termination-point/local-link-connectivities" {
     when '../../../../nw:network-types/tet:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Augmentation for TE node TTP LLCs (Local Link
        Connectivities).";
     uses te-node-tunnel-termination-point-llc-list;
   }
 }
 <CODE ENDS>

8. Security Considerations

 The YANG module specified in this document defines a schema for data
 that is designed to be accessed via network management protocols such
 as NETCONF [RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer
 is the secure transport layer, and the mandatory-to-implement secure
 transport is Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer
 is HTTPS, and the mandatory-to-implement secure transport is TLS
 [RFC8446].
 The Network Configuration Access Control Model (NACM) [RFC8341]
 provides the means to restrict access for particular NETCONF or
 RESTCONF users to a preconfigured subset of all available NETCONF or
 RESTCONF protocol operations and content.
 There are a number of data nodes defined in this YANG module that are
 writable/creatable/deletable (i.e., config true, which is the
 default).  These data nodes may be considered sensitive or vulnerable
 in some network environments.  Write operations (e.g., edit-config)
 to these data nodes without proper protection can have a negative
 effect on network operations.  These are the subtrees and data nodes
 and their sensitivity/vulnerability:
  • /nw:networks/nw:network/nw:network-types/tet:te-topology
    This subtree specifies the TE topology type.  Modifying the
    configurations can render the TE topology type invalid.  By making
    such modifications, a malicious attacker may disable the TE
    capabilities on the related networks and cause traffic to be
    disrupted or misrouted.
  • /nw:networks/tet:te
    This subtree specifies the TE node templates and TE link
    templates.  Modifying the configurations in this subtree will
    change the related future TE configurations.  By making such
    modifications, a malicious attacker may change TE capabilities
    scheduled at a future time and cause traffic to be disrupted or
    misrouted.
  • /nw:networks/nw:network
    This subtree specifies the topology-wide configurations, including
    the TE topology ID and topology-wide policies.  Modifying the
    configurations in this subtree can add, remove, or modify TE
    topologies.  By adding a TE topology, a malicious attacker may
    create an unauthorized traffic network.  By removing or modifying
    a TE topology, a malicious attacker may cause traffic to be
    disabled or misrouted in the specified TE topology.  Such traffic
    changes may also affect the traffic in the connected TE
    topologies.
  • /nw:networks/nw:network/nw:node
    This subtree specifies the configurations for TE nodes.  Modifying
    the configurations in this subtree can add, remove, or modify TE
    nodes.  By adding a TE node, a malicious attacker may create an
    unauthorized traffic path.  By removing or modifying a TE node, a
    malicious attacker may cause traffic to be disabled or misrouted
    in the specified TE node.  Such traffic changes may also affect
    the traffic on the surrounding TE nodes and TE links in this TE
    topology and the connected TE topologies.
  • /nw:networks/nw:network/nt:link/tet:te
    This subtree specifies the configurations for TE links.  Modifying
    the configurations in this subtree can add, remove, or modify TE
    links.  By adding a TE link, a malicious attacker may create an
    unauthorized traffic path.  By removing or modifying a TE link, a
    malicious attacker may cause traffic to be disabled or misrouted
    on the specified TE link.  Such traffic changes may also affect
    the traffic on the surrounding TE nodes and TE links in this TE
    topology and the connected TE topologies.
  • /nw:networks/nw:network/nw:node/nt:termination-point
    This subtree specifies the configurations of TE LTPs.  Modifying
    the configurations in this subtree can add, remove, or modify TE
    LTPs.  By adding a TE LTP, a malicious attacker may create an
    unauthorized traffic path.  By removing or modifying a TE LTP, a
    malicious attacker may cause traffic to be disabled or misrouted
    on the specified TE LTP.  Such traffic changes may also affect the
    traffic on the surrounding TE nodes and TE links in this TE
    topology and the connected TE topologies.
 Some of the readable data nodes in this YANG module may be considered
 sensitive or vulnerable in some network environments.  It is thus
 important to control read access (e.g., via get, get-config, or
 notification) to these data nodes.  These are the subtrees and data
 nodes and their sensitivity/vulnerability:
  • /nw:networks/nw:network/nw:network-types/tet:te-topology
    Unauthorized access to this subtree can disclose the TE topology
    type.
  • /nw:networks/tet:te
    Unauthorized access to this subtree can disclose the TE node
    templates and TE link templates.
  • /nw:networks/nw:network
    Unauthorized access to this subtree can disclose the topology-wide
    configurations, including the TE topology ID, the topology-wide
    policies, and the topology geolocation.
  • /nw:networks/nw:network/nw:node
    Unauthorized access to this subtree can disclose the operational
    state information of TE nodes.
  • /nw:networks/nw:network/nt:link/tet:te
    Unauthorized access to this subtree can disclose the operational
    state information of TE links.
  • /nw:networks/nw:network/nw:node/nt:termination-point
    Unauthorized access to this subtree can disclose the operational
    state information of TE LTPs.

9. IANA Considerations

 IANA has registered the following URIs in the "ns" subregistry within
 the "IETF XML Registry" [RFC3688].
 URI:  urn:ietf:params:xml:ns:yang:ietf-te-topology
 Registrant Contact:  The IESG.
 XML:  N/A; the requested URI is an XML namespace.
 URI:  urn:ietf:params:xml:ns:yang:ietf-te-topology-state
 Registrant Contact:  The IESG.
 XML:  N/A; the requested URI is an XML namespace.
 IANA has registered the following YANG modules in the "YANG Module
 Names" subregistry [RFC6020] within the "YANG Parameters" registry.
 Name:  ietf-te-topology
 Namespace:  urn:ietf:params:xml:ns:yang:ietf-te-topology
 Prefix:  tet
 Reference:  RFC 8795
 Name:  ietf-te-topology-state
 Namespace:  urn:ietf:params:xml:ns:yang:ietf-te-topology-state
 Prefix:  tet-s
 Reference:  RFC 8795

10. References

10.1. Normative References

 [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119,
            DOI 10.17487/RFC2119, March 1997,
            <https://www.rfc-editor.org/info/rfc2119>.
 [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
            DOI 10.17487/RFC3688, January 2004,
            <https://www.rfc-editor.org/info/rfc3688>.
 [RFC3945]  Mannie, E., Ed., "Generalized Multi-Protocol Label
            Switching (GMPLS) Architecture", RFC 3945,
            DOI 10.17487/RFC3945, October 2004,
            <https://www.rfc-editor.org/info/rfc3945>.
 [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
            the Network Configuration Protocol (NETCONF)", RFC 6020,
            DOI 10.17487/RFC6020, October 2010,
            <https://www.rfc-editor.org/info/rfc6020>.
 [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
            and A. Bierman, Ed., "Network Configuration Protocol
            (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
            <https://www.rfc-editor.org/info/rfc6241>.
 [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
            Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
            <https://www.rfc-editor.org/info/rfc6242>.
 [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
            RFC 6991, DOI 10.17487/RFC6991, July 2013,
            <https://www.rfc-editor.org/info/rfc6991>.
 [RFC7926]  Farrel, A., Ed., Drake, J., Bitar, N., Swallow, G.,
            Ceccarelli, D., and X. Zhang, "Problem Statement and
            Architecture for Information Exchange between
            Interconnected Traffic-Engineered Networks", BCP 206,
            RFC 7926, DOI 10.17487/RFC7926, July 2016,
            <https://www.rfc-editor.org/info/rfc7926>.
 [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
            RFC 7950, DOI 10.17487/RFC7950, August 2016,
            <https://www.rfc-editor.org/info/rfc7950>.
 [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
            Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
            <https://www.rfc-editor.org/info/rfc8040>.
 [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
            2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
            May 2017, <https://www.rfc-editor.org/info/rfc8174>.
 [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
            Access Control Model", STD 91, RFC 8341,
            DOI 10.17487/RFC8341, March 2018,
            <https://www.rfc-editor.org/info/rfc8341>.
 [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
            and R. Wilton, "Network Management Datastore Architecture
            (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
            <https://www.rfc-editor.org/info/rfc8342>.
 [RFC8345]  Clemm, A., Medved, J., Varga, R., Bahadur, N.,
            Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
            Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March
            2018, <https://www.rfc-editor.org/info/rfc8345>.
 [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
            Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
            <https://www.rfc-editor.org/info/rfc8446>.
 [RFC8776]  Saad, T., Gandhi, R., Liu, X., Beeram, V., and I. Bryskin,
            "Common YANG Data Types for Traffic Engineering",
            RFC 8776, DOI 10.17487/RFC8776, June 2020,
            <https://www.rfc-editor.org/info/rfc8776>.

10.2. Informative References

 [G.709]    ITU-T, "Interfaces for the optical transport network",
            ITU-T Recommendation G.709, June 2020,
            <https://www.itu.int/rec/T-REC-G.709/>.
 [G.805]    ITU-T, "Generic functional architecture of transport
            networks", ITU-T Recommendation G.805, March 2000,
            <https://www.itu.int/rec/T-REC-G.805/en>.
 [G.8080]   ITU-T, "Architecture for the automatically switched
            optical network", ITU-T Recommendation G.8080, February
            2012, <https://www.itu.int/rec/T-REC-G.8080/en>.
 [G.872]    ITU-T, "Architecture of optical transport networks",
            ITU-T Recommendation G.872, December 2019,
            <https://www.itu.int/rec/T-REC-G.872/en>.
 [RFC1195]  Callon, R., "Use of OSI IS-IS for routing in TCP/IP and
            dual environments", RFC 1195, DOI 10.17487/RFC1195,
            December 1990, <https://www.rfc-editor.org/info/rfc1195>.
 [RFC2702]  Awduche, D., Malcolm, J., Agogbua, J., O'Dell, M., and J.
            McManus, "Requirements for Traffic Engineering Over MPLS",
            RFC 2702, DOI 10.17487/RFC2702, September 1999,
            <https://www.rfc-editor.org/info/rfc2702>.
 [RFC3209]  Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
            and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
            Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
            <https://www.rfc-editor.org/info/rfc3209>.
 [RFC3272]  Awduche, D., Chiu, A., Elwalid, A., Widjaja, I., and X.
            Xiao, "Overview and Principles of Internet Traffic
            Engineering", RFC 3272, DOI 10.17487/RFC3272, May 2002,
            <https://www.rfc-editor.org/info/rfc3272>.
 [RFC3471]  Berger, L., Ed., "Generalized Multi-Protocol Label
            Switching (GMPLS) Signaling Functional Description",
            RFC 3471, DOI 10.17487/RFC3471, January 2003,
            <https://www.rfc-editor.org/info/rfc3471>.
 [RFC3630]  Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
            (TE) Extensions to OSPF Version 2", RFC 3630,
            DOI 10.17487/RFC3630, September 2003,
            <https://www.rfc-editor.org/info/rfc3630>.
 [RFC3785]  Le Faucheur, F., Uppili, R., Vedrenne, A., Merckx, P., and
            T. Telkamp, "Use of Interior Gateway Protocol (IGP) Metric
            as a second MPLS Traffic Engineering (TE) Metric", BCP 87,
            RFC 3785, DOI 10.17487/RFC3785, May 2004,
            <https://www.rfc-editor.org/info/rfc3785>.
 [RFC4201]  Kompella, K., Rekhter, Y., and L. Berger, "Link Bundling
            in MPLS Traffic Engineering (TE)", RFC 4201,
            DOI 10.17487/RFC4201, October 2005,
            <https://www.rfc-editor.org/info/rfc4201>.
 [RFC4202]  Kompella, K., Ed. and Y. Rekhter, Ed., "Routing Extensions
            in Support of Generalized Multi-Protocol Label Switching
            (GMPLS)", RFC 4202, DOI 10.17487/RFC4202, October 2005,
            <https://www.rfc-editor.org/info/rfc4202>.
 [RFC4203]  Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in
            Support of Generalized Multi-Protocol Label Switching
            (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005,
            <https://www.rfc-editor.org/info/rfc4203>.
 [RFC4206]  Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP)
            Hierarchy with Generalized Multi-Protocol Label Switching
            (GMPLS) Traffic Engineering (TE)", RFC 4206,
            DOI 10.17487/RFC4206, October 2005,
            <https://www.rfc-editor.org/info/rfc4206>.
 [RFC4872]  Lang, J.P., Ed., Rekhter, Y., Ed., and D. Papadimitriou,
            Ed., "RSVP-TE Extensions in Support of End-to-End
            Generalized Multi-Protocol Label Switching (GMPLS)
            Recovery", RFC 4872, DOI 10.17487/RFC4872, May 2007,
            <https://www.rfc-editor.org/info/rfc4872>.
 [RFC5152]  Vasseur, JP., Ed., Ayyangar, A., Ed., and R. Zhang, "A
            Per-Domain Path Computation Method for Establishing Inter-
            Domain Traffic Engineering (TE) Label Switched Paths
            (LSPs)", RFC 5152, DOI 10.17487/RFC5152, February 2008,
            <https://www.rfc-editor.org/info/rfc5152>.
 [RFC5212]  Shiomoto, K., Papadimitriou, D., Le Roux, JL., Vigoureux,
            M., and D. Brungard, "Requirements for GMPLS-Based Multi-
            Region and Multi-Layer Networks (MRN/MLN)", RFC 5212,
            DOI 10.17487/RFC5212, July 2008,
            <https://www.rfc-editor.org/info/rfc5212>.
 [RFC5305]  Li, T. and H. Smit, "IS-IS Extensions for Traffic
            Engineering", RFC 5305, DOI 10.17487/RFC5305, October
            2008, <https://www.rfc-editor.org/info/rfc5305>.
 [RFC5316]  Chen, M., Zhang, R., and X. Duan, "ISIS Extensions in
            Support of Inter-Autonomous System (AS) MPLS and GMPLS
            Traffic Engineering", RFC 5316, DOI 10.17487/RFC5316,
            December 2008, <https://www.rfc-editor.org/info/rfc5316>.
 [RFC5392]  Chen, M., Zhang, R., and X. Duan, "OSPF Extensions in
            Support of Inter-Autonomous System (AS) MPLS and GMPLS
            Traffic Engineering", RFC 5392, DOI 10.17487/RFC5392,
            January 2009, <https://www.rfc-editor.org/info/rfc5392>.
 [RFC6001]  Papadimitriou, D., Vigoureux, M., Shiomoto, K., Brungard,
            D., and JL. Le Roux, "Generalized MPLS (GMPLS) Protocol
            Extensions for Multi-Layer and Multi-Region Networks (MLN/
            MRN)", RFC 6001, DOI 10.17487/RFC6001, October 2010,
            <https://www.rfc-editor.org/info/rfc6001>.
 [RFC7308]  Osborne, E., "Extended Administrative Groups in MPLS
            Traffic Engineering (MPLS-TE)", RFC 7308,
            DOI 10.17487/RFC7308, July 2014,
            <https://www.rfc-editor.org/info/rfc7308>.
 [RFC7471]  Giacalone, S., Ward, D., Drake, J., Atlas, A., and S.
            Previdi, "OSPF Traffic Engineering (TE) Metric
            Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015,
            <https://www.rfc-editor.org/info/rfc7471>.
 [RFC7579]  Bernstein, G., Ed., Lee, Y., Ed., Li, D., Imajuku, W., and
            J. Han, "General Network Element Constraint Encoding for
            GMPLS-Controlled Networks", RFC 7579,
            DOI 10.17487/RFC7579, June 2015,
            <https://www.rfc-editor.org/info/rfc7579>.
 [RFC7752]  Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and
            S. Ray, "North-Bound Distribution of Link-State and
            Traffic Engineering (TE) Information Using BGP", RFC 7752,
            DOI 10.17487/RFC7752, March 2016,
            <https://www.rfc-editor.org/info/rfc7752>.
 [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
            BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
            <https://www.rfc-editor.org/info/rfc8340>.
 [RFC8639]  Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
            E., and A. Tripathy, "Subscription to YANG Notifications",
            RFC 8639, DOI 10.17487/RFC8639, September 2019,
            <https://www.rfc-editor.org/info/rfc8639>.
 [RFC8641]  Clemm, A. and E. Voit, "Subscription to YANG Notifications
            for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641,
            September 2019, <https://www.rfc-editor.org/info/rfc8641>.
 [TEAS-TOPO]
            Bryskin, I., Beeram, V., Saad, T., and X. Liu, "TE
            Topology and Tunnel Modeling for Transport Networks", Work
            in Progress, Internet-Draft, draft-ietf-teas-te-topo-and-
            tunnel-modeling-06, 12 July 2020,
            <https://tools.ietf.org/html/draft-ietf-teas-te-topo-and-
            tunnel-modeling-06>.
 [YANG-CFG-SCHED]
            Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
            O. Gonzalez de Dios, "A YANG Data Model for Configuration
            Scheduling", Work in Progress, Internet-Draft, draft-liu-
            netmod-yang-schedule-05, 1 March 2018,
            <https://tools.ietf.org/html/draft-liu-netmod-yang-
            schedule-05>.
 [YANG-L3]  Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
            O. Gonzalez de Dios, "YANG Data Model for Layer 3 TE
            Topologies", Work in Progress, Internet-Draft, draft-ietf-
            teas-yang-l3-te-topo-08, 12 July 2020,
            <https://tools.ietf.org/html/draft-ietf-teas-yang-l3-te-
            topo-08>.
 [YANG-OTN] Zheng, H., Busi, I., Liu, X., Belotti, S., and O. Gonzalez
            de Dios, "A YANG Data Model for Optical Transport Network
            Topology", Work in Progress, Internet-Draft, draft-ietf-
            ccamp-otn-topo-yang-10, 9 March 2020,
            <https://tools.ietf.org/html/draft-ietf-ccamp-otn-topo-
            yang-10>.
 [YANG-WSON]
            Zheng, H., Lee, Y., Guo, A., Lopez, V., and D. King, "A
            YANG Data Model for WSON (Wavelength Switched Optical
            Networks)", Work in Progress, Internet-Draft, draft-ietf-
            ccamp-wson-yang-25, 19 May 2020,
            <https://tools.ietf.org/html/draft-ietf-ccamp-wson-yang-
            25>.

Appendix A. Complete Model Tree Structure

 module: ietf-te-topology
   augment /nw:networks/nw:network/nw:network-types:
     +--rw te-topology!
   augment /nw:networks:
     +--rw te!
        +--rw templates
           +--rw node-template* [name] {template}?
           |  +--rw name
           |  |       te-types:te-template-name
           |  +--rw priority?                  uint16
           |  +--rw reference-change-policy?   enumeration
           |  +--rw te-node-attributes
           |     +--rw admin-status?        te-types:te-admin-status
           |     +--rw domain-id?           uint32
           |     +--rw is-abstract?         empty
           |     +--rw name?                string
           |     +--rw signaling-address*   inet:ip-address
           |     +--rw underlay-topology {te-topology-hierarchy}?
           |        +--rw network-ref?
           |                -> /nw:networks/network/network-id
           +--rw link-template* [name] {template}?
              +--rw name
              |       te-types:te-template-name
              +--rw priority?                  uint16
              +--rw reference-change-policy?   enumeration
              +--rw te-link-attributes
                 +--rw access-type?
                 |       te-types:te-link-access-type
                 +--rw external-domain
                 |  +--rw network-ref?
                 |  |       -> /nw:networks/network/network-id
                 |  +--rw remote-te-node-id?      te-types:te-node-id
                 |  +--rw remote-te-link-tp-id?   te-types:te-tp-id
                 +--rw is-abstract?                      empty
                 +--rw name?                             string
                 +--rw underlay {te-topology-hierarchy}?
                 |  +--rw enabled?                     boolean
                 |  +--rw primary-path
                 |  |  +--rw network-ref?
                 |  |  |       -> /nw:networks/network/network-id
                 |  |  +--rw path-element* [path-element-id]
                 |  |     +--rw path-element-id              uint32
                 |  |     +--rw (type)?
                 |  |        +--:(numbered-node-hop)
                 |  |        |  +--rw numbered-node-hop
                 |  |        |     +--rw node-id     te-node-id
                 |  |        |     +--rw hop-type?   te-hop-type
                 |  |        +--:(numbered-link-hop)
                 |  |        |  +--rw numbered-link-hop
                 |  |        |     +--rw link-tp-id    te-tp-id
                 |  |        |     +--rw hop-type?     te-hop-type
                 |  |        |     +--rw direction?
                 |  |        |             te-link-direction
                 |  |        +--:(unnumbered-link-hop)
                 |  |        |  +--rw unnumbered-link-hop
                 |  |        |     +--rw link-tp-id    te-tp-id
                 |  |        |     +--rw node-id       te-node-id
                 |  |        |     +--rw hop-type?     te-hop-type
                 |  |        |     +--rw direction?
                 |  |        |             te-link-direction
                 |  |        +--:(as-number)
                 |  |        |  +--rw as-number-hop
                 |  |        |     +--rw as-number    inet:as-number
                 |  |        |     +--rw hop-type?    te-hop-type
                 |  |        +--:(label)
                 |  |           +--rw label-hop
                 |  |              +--rw te-label
                 |  |                 +--rw (technology)?
                 |  |                 |  +--:(generic)
                 |  |                 |     +--rw generic?
                 |  |                 |             rt-
 types:generalized-label
                 |  |                 +--rw direction?
                 |  |                         te-label-direction
                 |  +--rw backup-path* [index]
                 |  |  +--rw index           uint32
                 |  |  +--rw network-ref?
                 |  |  |       -> /nw:networks/network/network-id
                 |  |  +--rw path-element* [path-element-id]
                 |  |     +--rw path-element-id              uint32
                 |  |     +--rw (type)?
                 |  |        +--:(numbered-node-hop)
                 |  |        |  +--rw numbered-node-hop
                 |  |        |     +--rw node-id     te-node-id
                 |  |        |     +--rw hop-type?   te-hop-type
                 |  |        +--:(numbered-link-hop)
                 |  |        |  +--rw numbered-link-hop
                 |  |        |     +--rw link-tp-id    te-tp-id
                 |  |        |     +--rw hop-type?     te-hop-type
                 |  |        |     +--rw direction?
                 |  |        |             te-link-direction
                 |  |        +--:(unnumbered-link-hop)
                 |  |        |  +--rw unnumbered-link-hop
                 |  |        |     +--rw link-tp-id    te-tp-id
                 |  |        |     +--rw node-id       te-node-id
                 |  |        |     +--rw hop-type?     te-hop-type
                 |  |        |     +--rw direction?
                 |  |        |             te-link-direction
                 |  |        +--:(as-number)
                 |  |        |  +--rw as-number-hop
                 |  |        |     +--rw as-number    inet:as-number
                 |  |        |     +--rw hop-type?    te-hop-type
                 |  |        +--:(label)
                 |  |           +--rw label-hop
                 |  |              +--rw te-label
                 |  |                 +--rw (technology)?
                 |  |                 |  +--:(generic)
                 |  |                 |     +--rw generic?
                 |  |                 |             rt-
 types:generalized-label
                 |  |                 +--rw direction?
                 |  |                         te-label-direction
                 |  +--rw protection-type?             identityref
                 |  +--rw tunnel-termination-points
                 |  |  +--rw source?        binary
                 |  |  +--rw destination?   binary
                 |  +--rw tunnels
                 |     +--rw sharing?   boolean
                 |     +--rw tunnel* [tunnel-name]
                 |        +--rw tunnel-name    string
                 |        +--rw sharing?       boolean
                 +--rw admin-status?
                 |       te-types:te-admin-status
                 +--rw link-index?                       uint64
                 +--rw administrative-group?
                 |       te-types:admin-groups
                 +--rw interface-switching-capability*
                 |       [switching-capability encoding]
                 |  +--rw switching-capability    identityref
                 |  +--rw encoding                identityref
                 |  +--rw max-lsp-bandwidth* [priority]
                 |     +--rw priority        uint8
                 |     +--rw te-bandwidth
                 |        +--rw (technology)?
                 |           +--:(generic)
                 |              +--rw generic?   te-bandwidth
                 +--rw label-restrictions
                 |  +--rw label-restriction* [index]
                 |     +--rw restriction?    enumeration
                 |     +--rw index           uint32
                 |     +--rw label-start
                 |     |  +--rw te-label
                 |     |     +--rw (technology)?
                 |     |     |  +--:(generic)
                 |     |     |     +--rw generic?
                 |     |     |             rt-types:generalized-label
                 |     |     +--rw direction?       te-label-direction
                 |     +--rw label-end
                 |     |  +--rw te-label
                 |     |     +--rw (technology)?
                 |     |     |  +--:(generic)
                 |     |     |     +--rw generic?
                 |     |     |             rt-types:generalized-label
                 |     |     +--rw direction?       te-label-direction
                 |     +--rw label-step
                 |     |  +--rw (technology)?
                 |     |     +--:(generic)
                 |     |        +--rw generic?   int32
                 |     +--rw range-bitmap?   yang:hex-string
                 +--rw link-protection-type?             identityref
                 +--rw max-link-bandwidth
                 |  +--rw te-bandwidth
                 |     +--rw (technology)?
                 |        +--:(generic)
                 |           +--rw generic?   te-bandwidth
                 +--rw max-resv-link-bandwidth
                 |  +--rw te-bandwidth
                 |     +--rw (technology)?
                 |        +--:(generic)
                 |           +--rw generic?   te-bandwidth
                 +--rw unreserved-bandwidth* [priority]
                 |  +--rw priority        uint8
                 |  +--rw te-bandwidth
                 |     +--rw (technology)?
                 |        +--:(generic)
                 |           +--rw generic?   te-bandwidth
                 +--rw te-default-metric?                uint32
                 +--rw te-delay-metric?                  uint32
                 +--rw te-igp-metric?                    uint32
                 +--rw te-srlgs
                 |  +--rw value*   te-types:srlg
                 +--rw te-nsrlgs {nsrlg}?
                    +--rw id*   uint32
   augment /nw:networks/nw:network:
     +--rw te-topology-identifier
     |  +--rw provider-id?   te-global-id
     |  +--rw client-id?     te-global-id
     |  +--rw topology-id?   te-topology-id
     +--rw te!
        +--rw name?                     string
        +--rw preference?               uint8
        +--rw optimization-criterion?   identityref
        +--rw nsrlg* [id] {nsrlg}?
        |  +--rw id              uint32
        |  +--rw disjointness?   te-types:te-path-disjointness
        +--ro geolocation
           +--ro altitude?    int64
           +--ro latitude?    geographic-coordinate-degree
           +--ro longitude?   geographic-coordinate-degree
   augment /nw:networks/nw:network/nw:node:
     +--rw te-node-id?   te-types:te-node-id
     +--rw te!
        +--rw te-node-template*
        |       -> ../../../../te/templates/node-template/name
        |       {template}?
        +--rw te-node-attributes
        |  +--rw admin-status?            te-types:te-admin-status
        |  +--rw connectivity-matrices
        |  |  +--rw number-of-entries?     uint16
        |  |  +--rw label-restrictions
        |  |  |  +--rw label-restriction* [index]
        |  |  |     +--rw restriction?    enumeration
        |  |  |     +--rw index           uint32
        |  |  |     +--rw label-start
        |  |  |     |  +--rw te-label
        |  |  |     |     +--rw (technology)?
        |  |  |     |     |  +--:(generic)
        |  |  |     |     |     +--rw generic?
        |  |  |     |     |             rt-types:generalized-label
        |  |  |     |     +--rw direction?       te-label-direction
        |  |  |     +--rw label-end
        |  |  |     |  +--rw te-label
        |  |  |     |     +--rw (technology)?
        |  |  |     |     |  +--:(generic)
        |  |  |     |     |     +--rw generic?
        |  |  |     |     |             rt-types:generalized-label
        |  |  |     |     +--rw direction?       te-label-direction
        |  |  |     +--rw label-step
        |  |  |     |  +--rw (technology)?
        |  |  |     |     +--:(generic)
        |  |  |     |        +--rw generic?   int32
        |  |  |     +--rw range-bitmap?   yang:hex-string
        |  |  +--rw is-allowed?            boolean
        |  |  +--rw underlay {te-topology-hierarchy}?
        |  |  |  +--rw enabled?                     boolean
        |  |  |  +--rw primary-path
        |  |  |  |  +--rw network-ref?
        |  |  |  |  |       -> /nw:networks/network/network-id
        |  |  |  |  +--rw path-element* [path-element-id]
        |  |  |  |     +--rw path-element-id              uint32
        |  |  |  |     +--rw (type)?
        |  |  |  |        +--:(numbered-node-hop)
        |  |  |  |        |  +--rw numbered-node-hop
        |  |  |  |        |     +--rw node-id     te-node-id
        |  |  |  |        |     +--rw hop-type?   te-hop-type
        |  |  |  |        +--:(numbered-link-hop)
        |  |  |  |        |  +--rw numbered-link-hop
        |  |  |  |        |     +--rw link-tp-id    te-tp-id
        |  |  |  |        |     +--rw hop-type?     te-hop-type
        |  |  |  |        |     +--rw direction?    te-link-direction
        |  |  |  |        +--:(unnumbered-link-hop)
        |  |  |  |        |  +--rw unnumbered-link-hop
        |  |  |  |        |     +--rw link-tp-id    te-tp-id
        |  |  |  |        |     +--rw node-id       te-node-id
        |  |  |  |        |     +--rw hop-type?     te-hop-type
        |  |  |  |        |     +--rw direction?    te-link-direction
        |  |  |  |        +--:(as-number)
        |  |  |  |        |  +--rw as-number-hop
        |  |  |  |        |     +--rw as-number    inet:as-number
        |  |  |  |        |     +--rw hop-type?    te-hop-type
        |  |  |  |        +--:(label)
        |  |  |  |           +--rw label-hop
        |  |  |  |              +--rw te-label
        |  |  |  |                 +--rw (technology)?
        |  |  |  |                 |  +--:(generic)
        |  |  |  |                 |     +--rw generic?
        |  |  |  |                 |             rt-types:generalized-
 label
        |  |  |  |                 +--rw direction?
        |  |  |  |                         te-label-direction
        |  |  |  +--rw backup-path* [index]
        |  |  |  |  +--rw index           uint32
        |  |  |  |  +--rw network-ref?
        |  |  |  |  |       -> /nw:networks/network/network-id
        |  |  |  |  +--rw path-element* [path-element-id]
        |  |  |  |     +--rw path-element-id              uint32
        |  |  |  |     +--rw (type)?
        |  |  |  |        +--:(numbered-node-hop)
        |  |  |  |        |  +--rw numbered-node-hop
        |  |  |  |        |     +--rw node-id     te-node-id
        |  |  |  |        |     +--rw hop-type?   te-hop-type
        |  |  |  |        +--:(numbered-link-hop)
        |  |  |  |        |  +--rw numbered-link-hop
        |  |  |  |        |     +--rw link-tp-id    te-tp-id
        |  |  |  |        |     +--rw hop-type?     te-hop-type
        |  |  |  |        |     +--rw direction?    te-link-direction
        |  |  |  |        +--:(unnumbered-link-hop)
        |  |  |  |        |  +--rw unnumbered-link-hop
        |  |  |  |        |     +--rw link-tp-id    te-tp-id
        |  |  |  |        |     +--rw node-id       te-node-id
        |  |  |  |        |     +--rw hop-type?     te-hop-type
        |  |  |  |        |     +--rw direction?    te-link-direction
        |  |  |  |        +--:(as-number)
        |  |  |  |        |  +--rw as-number-hop
        |  |  |  |        |     +--rw as-number    inet:as-number
        |  |  |  |        |     +--rw hop-type?    te-hop-type
        |  |  |  |        +--:(label)
        |  |  |  |           +--rw label-hop
        |  |  |  |              +--rw te-label
        |  |  |  |                 +--rw (technology)?
        |  |  |  |                 |  +--:(generic)
        |  |  |  |                 |     +--rw generic?
        |  |  |  |                 |             rt-types:generalized-
 label
        |  |  |  |                 +--rw direction?
        |  |  |  |                         te-label-direction
        |  |  |  +--rw protection-type?             identityref
        |  |  |  +--rw tunnel-termination-points
        |  |  |  |  +--rw source?        binary
        |  |  |  |  +--rw destination?   binary
        |  |  |  +--rw tunnels
        |  |  |     +--rw sharing?   boolean
        |  |  |     +--rw tunnel* [tunnel-name]
        |  |  |        +--rw tunnel-name    string
        |  |  |        +--rw sharing?       boolean
        |  |  +--rw path-constraints
        |  |  |  +--rw te-bandwidth
        |  |  |  |  +--rw (technology)?
        |  |  |  |     +--:(generic)
        |  |  |  |        +--rw generic?   te-bandwidth
        |  |  |  +--rw link-protection?          identityref
        |  |  |  +--rw setup-priority?           uint8
        |  |  |  +--rw hold-priority?            uint8
        |  |  |  +--rw signaling-type?           identityref
        |  |  |  +--rw path-metric-bounds
        |  |  |  |  +--rw path-metric-bound* [metric-type]
        |  |  |  |     +--rw metric-type    identityref
        |  |  |  |     +--rw upper-bound?   uint64
        |  |  |  +--rw path-affinities-values
        |  |  |  |  +--rw path-affinities-value* [usage]
        |  |  |  |     +--rw usage    identityref
        |  |  |  |     +--rw value?   admin-groups
        |  |  |  +--rw path-affinity-names
        |  |  |  |  +--rw path-affinity-name* [usage]
        |  |  |  |     +--rw usage            identityref
        |  |  |  |     +--rw affinity-name* [name]
        |  |  |  |        +--rw name    string
        |  |  |  +--rw path-srlgs-lists
        |  |  |  |  +--rw path-srlgs-list* [usage]
        |  |  |  |     +--rw usage     identityref
        |  |  |  |     +--rw values*   srlg
        |  |  |  +--rw path-srlgs-names
        |  |  |  |  +--rw path-srlgs-name* [usage]
        |  |  |  |     +--rw usage    identityref
        |  |  |  |     +--rw names*   string
        |  |  |  +--rw disjointness?             te-path-disjointness
        |  |  +--rw optimizations
        |  |  |  +--rw (algorithm)?
        |  |  |     +--:(metric) {path-optimization-metric}?
        |  |  |     |  +--rw optimization-metric* [metric-type]
        |  |  |     |  |  +--rw metric-type
        |  |  |     |  |  |       identityref
        |  |  |     |  |  +--rw weight?
        |  |  |     |  |  |       uint8
        |  |  |     |  |  +--rw explicit-route-exclude-objects
        |  |  |     |  |  |  +--rw route-object-exclude-object*
        |  |  |     |  |  |          [index]
        |  |  |     |  |  |     +--rw index
        |  |  |     |  |  |     |       uint32
        |  |  |     |  |  |     +--rw (type)?
        |  |  |     |  |  |        +--:(numbered-node-hop)
        |  |  |     |  |  |        |  +--rw numbered-node-hop
        |  |  |     |  |  |        |     +--rw node-id     te-node-id
        |  |  |     |  |  |        |     +--rw hop-type?   te-hop-type
        |  |  |     |  |  |        +--:(numbered-link-hop)
        |  |  |     |  |  |        |  +--rw numbered-link-hop
        |  |  |     |  |  |        |     +--rw link-tp-id    te-tp-id
        |  |  |     |  |  |        |     +--rw hop-type?
        |  |  |     |  |  |        |     |       te-hop-type
        |  |  |     |  |  |        |     +--rw direction?
        |  |  |     |  |  |        |             te-link-direction
        |  |  |     |  |  |        +--:(unnumbered-link-hop)
        |  |  |     |  |  |        |  +--rw unnumbered-link-hop
        |  |  |     |  |  |        |     +--rw link-tp-id    te-tp-id
        |  |  |     |  |  |        |     +--rw node-id
        |  |  |     |  |  |        |     |       te-node-id
        |  |  |     |  |  |        |     +--rw hop-type?
        |  |  |     |  |  |        |     |       te-hop-type
        |  |  |     |  |  |        |     +--rw direction?
        |  |  |     |  |  |        |             te-link-direction
        |  |  |     |  |  |        +--:(as-number)
        |  |  |     |  |  |        |  +--rw as-number-hop
        |  |  |     |  |  |        |     +--rw as-number
        |  |  |     |  |  |        |     |       inet:as-number
        |  |  |     |  |  |        |     +--rw hop-type?
        |  |  |     |  |  |        |             te-hop-type
        |  |  |     |  |  |        +--:(label)
        |  |  |     |  |  |        |  +--rw label-hop
        |  |  |     |  |  |        |     +--rw te-label
        |  |  |     |  |  |        |        +--rw (technology)?
        |  |  |     |  |  |        |        |  +--:(generic)
        |  |  |     |  |  |        |        |     +--rw generic?
        |  |  |     |  |  |        |        |             rt-
 types:generalized-label
        |  |  |     |  |  |        |        +--rw direction?
        |  |  |     |  |  |        |                te-label-direction
        |  |  |     |  |  |        +--:(srlg)
        |  |  |     |  |  |           +--rw srlg
        |  |  |     |  |  |              +--rw srlg?   uint32
        |  |  |     |  |  +--rw explicit-route-include-objects
        |  |  |     |  |     +--rw route-object-include-object*
        |  |  |     |  |             [index]
        |  |  |     |  |        +--rw index
        |  |  |     |  |        |       uint32
        |  |  |     |  |        +--rw (type)?
        |  |  |     |  |           +--:(numbered-node-hop)
        |  |  |     |  |           |  +--rw numbered-node-hop
        |  |  |     |  |           |     +--rw node-id     te-node-id
        |  |  |     |  |           |     +--rw hop-type?   te-hop-type
        |  |  |     |  |           +--:(numbered-link-hop)
        |  |  |     |  |           |  +--rw numbered-link-hop
        |  |  |     |  |           |     +--rw link-tp-id    te-tp-id
        |  |  |     |  |           |     +--rw hop-type?
        |  |  |     |  |           |     |       te-hop-type
        |  |  |     |  |           |     +--rw direction?
        |  |  |     |  |           |             te-link-direction
        |  |  |     |  |           +--:(unnumbered-link-hop)
        |  |  |     |  |           |  +--rw unnumbered-link-hop
        |  |  |     |  |           |     +--rw link-tp-id    te-tp-id
        |  |  |     |  |           |     +--rw node-id
        |  |  |     |  |           |     |       te-node-id
        |  |  |     |  |           |     +--rw hop-type?
        |  |  |     |  |           |     |       te-hop-type
        |  |  |     |  |           |     +--rw direction?
        |  |  |     |  |           |             te-link-direction
        |  |  |     |  |           +--:(as-number)
        |  |  |     |  |           |  +--rw as-number-hop
        |  |  |     |  |           |     +--rw as-number
        |  |  |     |  |           |     |       inet:as-number
        |  |  |     |  |           |     +--rw hop-type?
        |  |  |     |  |           |             te-hop-type
        |  |  |     |  |           +--:(label)
        |  |  |     |  |              +--rw label-hop
        |  |  |     |  |                 +--rw te-label
        |  |  |     |  |                    +--rw (technology)?
        |  |  |     |  |                    |  +--:(generic)
        |  |  |     |  |                    |     +--rw generic?
        |  |  |     |  |                    |             rt-
 types:generalized-label
        |  |  |     |  |                    +--rw direction?
        |  |  |     |  |                            te-label-direction
        |  |  |     |  +--rw tiebreakers
        |  |  |     |     +--rw tiebreaker* [tiebreaker-type]
        |  |  |     |        +--rw tiebreaker-type    identityref
        |  |  |     +--:(objective-function)
        |  |  |              {path-optimization-objective-function}?
        |  |  |        +--rw objective-function
        |  |  |           +--rw objective-function-type?   identityref
        |  |  +--ro path-properties
        |  |  |  +--ro path-metric* [metric-type]
        |  |  |  |  +--ro metric-type           identityref
        |  |  |  |  +--ro accumulative-value?   uint64
        |  |  |  +--ro path-affinities-values
        |  |  |  |  +--ro path-affinities-value* [usage]
        |  |  |  |     +--ro usage    identityref
        |  |  |  |     +--ro value?   admin-groups
        |  |  |  +--ro path-affinity-names
        |  |  |  |  +--ro path-affinity-name* [usage]
        |  |  |  |     +--ro usage            identityref
        |  |  |  |     +--ro affinity-name* [name]
        |  |  |  |        +--ro name    string
        |  |  |  +--ro path-srlgs-lists
        |  |  |  |  +--ro path-srlgs-list* [usage]
        |  |  |  |     +--ro usage     identityref
        |  |  |  |     +--ro values*   srlg
        |  |  |  +--ro path-srlgs-names
        |  |  |  |  +--ro path-srlgs-name* [usage]
        |  |  |  |     +--ro usage    identityref
        |  |  |  |     +--ro names*   string
        |  |  |  +--ro path-route-objects
        |  |  |     +--ro path-route-object* [index]
        |  |  |        +--ro index                        uint32
        |  |  |        +--ro (type)?
        |  |  |           +--:(numbered-node-hop)
        |  |  |           |  +--ro numbered-node-hop
        |  |  |           |     +--ro node-id     te-node-id
        |  |  |           |     +--ro hop-type?   te-hop-type
        |  |  |           +--:(numbered-link-hop)
        |  |  |           |  +--ro numbered-link-hop
        |  |  |           |     +--ro link-tp-id    te-tp-id
        |  |  |           |     +--ro hop-type?     te-hop-type
        |  |  |           |     +--ro direction?    te-link-direction
        |  |  |           +--:(unnumbered-link-hop)
        |  |  |           |  +--ro unnumbered-link-hop
        |  |  |           |     +--ro link-tp-id    te-tp-id
        |  |  |           |     +--ro node-id       te-node-id
        |  |  |           |     +--ro hop-type?     te-hop-type
        |  |  |           |     +--ro direction?    te-link-direction
        |  |  |           +--:(as-number)
        |  |  |           |  +--ro as-number-hop
        |  |  |           |     +--ro as-number    inet:as-number
        |  |  |           |     +--ro hop-type?    te-hop-type
        |  |  |           +--:(label)
        |  |  |              +--ro label-hop
        |  |  |                 +--ro te-label
        |  |  |                    +--ro (technology)?
        |  |  |                    |  +--:(generic)
        |  |  |                    |     +--ro generic?
        |  |  |                    |             rt-types:generalized-
 label
        |  |  |                    +--ro direction?
        |  |  |                            te-label-direction
        |  |  +--rw connectivity-matrix* [id]
        |  |     +--rw id                  uint32
        |  |     +--rw from
        |  |     |  +--rw tp-ref?               leafref
        |  |     |  +--rw label-restrictions
        |  |     |     +--rw label-restriction* [index]
        |  |     |        +--rw restriction?    enumeration
        |  |     |        +--rw index           uint32
        |  |     |        +--rw label-start
        |  |     |        |  +--rw te-label
        |  |     |        |     +--rw (technology)?
        |  |     |        |     |  +--:(generic)
        |  |     |        |     |     +--rw generic?
        |  |     |        |     |             rt-types:generalized-
 label
        |  |     |        |     +--rw direction?
        |  |     |        |             te-label-direction
        |  |     |        +--rw label-end
        |  |     |        |  +--rw te-label
        |  |     |        |     +--rw (technology)?
        |  |     |        |     |  +--:(generic)
        |  |     |        |     |     +--rw generic?
        |  |     |        |     |             rt-types:generalized-
 label
        |  |     |        |     +--rw direction?
        |  |     |        |             te-label-direction
        |  |     |        +--rw label-step
        |  |     |        |  +--rw (technology)?
        |  |     |        |     +--:(generic)
        |  |     |        |        +--rw generic?   int32
        |  |     |        +--rw range-bitmap?   yang:hex-string
        |  |     +--rw to
        |  |     |  +--rw tp-ref?               leafref
        |  |     |  +--rw label-restrictions
        |  |     |     +--rw label-restriction* [index]
        |  |     |        +--rw restriction?    enumeration
        |  |     |        +--rw index           uint32
        |  |     |        +--rw label-start
        |  |     |        |  +--rw te-label
        |  |     |        |     +--rw (technology)?
        |  |     |        |     |  +--:(generic)
        |  |     |        |     |     +--rw generic?
        |  |     |        |     |             rt-types:generalized-
 label
        |  |     |        |     +--rw direction?
        |  |     |        |             te-label-direction
        |  |     |        +--rw label-end
        |  |     |        |  +--rw te-label
        |  |     |        |     +--rw (technology)?
        |  |     |        |     |  +--:(generic)
        |  |     |        |     |     +--rw generic?
        |  |     |        |     |             rt-types:generalized-
 label
        |  |     |        |     +--rw direction?
        |  |     |        |             te-label-direction
        |  |     |        +--rw label-step
        |  |     |        |  +--rw (technology)?
        |  |     |        |     +--:(generic)
        |  |     |        |        +--rw generic?   int32
        |  |     |        +--rw range-bitmap?   yang:hex-string
        |  |     +--rw is-allowed?         boolean
        |  |     +--rw underlay {te-topology-hierarchy}?
        |  |     |  +--rw enabled?                     boolean
        |  |     |  +--rw primary-path
        |  |     |  |  +--rw network-ref?
        |  |     |  |  |       -> /nw:networks/network/network-id
        |  |     |  |  +--rw path-element* [path-element-id]
        |  |     |  |     +--rw path-element-id              uint32
        |  |     |  |     +--rw (type)?
        |  |     |  |        +--:(numbered-node-hop)
        |  |     |  |        |  +--rw numbered-node-hop
        |  |     |  |        |     +--rw node-id     te-node-id
        |  |     |  |        |     +--rw hop-type?   te-hop-type
        |  |     |  |        +--:(numbered-link-hop)
        |  |     |  |        |  +--rw numbered-link-hop
        |  |     |  |        |     +--rw link-tp-id    te-tp-id
        |  |     |  |        |     +--rw hop-type?     te-hop-type
        |  |     |  |        |     +--rw direction?
        |  |     |  |        |             te-link-direction
        |  |     |  |        +--:(unnumbered-link-hop)
        |  |     |  |        |  +--rw unnumbered-link-hop
        |  |     |  |        |     +--rw link-tp-id    te-tp-id
        |  |     |  |        |     +--rw node-id       te-node-id
        |  |     |  |        |     +--rw hop-type?     te-hop-type
        |  |     |  |        |     +--rw direction?
        |  |     |  |        |             te-link-direction
        |  |     |  |        +--:(as-number)
        |  |     |  |        |  +--rw as-number-hop
        |  |     |  |        |     +--rw as-number    inet:as-number
        |  |     |  |        |     +--rw hop-type?    te-hop-type
        |  |     |  |        +--:(label)
        |  |     |  |           +--rw label-hop
        |  |     |  |              +--rw te-label
        |  |     |  |                 +--rw (technology)?
        |  |     |  |                 |  +--:(generic)
        |  |     |  |                 |     +--rw generic?
        |  |     |  |                 |             rt-
 types:generalized-label
        |  |     |  |                 +--rw direction?
        |  |     |  |                         te-label-direction
        |  |     |  +--rw backup-path* [index]
        |  |     |  |  +--rw index           uint32
        |  |     |  |  +--rw network-ref?
        |  |     |  |  |       -> /nw:networks/network/network-id
        |  |     |  |  +--rw path-element* [path-element-id]
        |  |     |  |     +--rw path-element-id              uint32
        |  |     |  |     +--rw (type)?
        |  |     |  |        +--:(numbered-node-hop)
        |  |     |  |        |  +--rw numbered-node-hop
        |  |     |  |        |     +--rw node-id     te-node-id
        |  |     |  |        |     +--rw hop-type?   te-hop-type
        |  |     |  |        +--:(numbered-link-hop)
        |  |     |  |        |  +--rw numbered-link-hop
        |  |     |  |        |     +--rw link-tp-id    te-tp-id
        |  |     |  |        |     +--rw hop-type?     te-hop-type
        |  |     |  |        |     +--rw direction?
        |  |     |  |        |             te-link-direction
        |  |     |  |        +--:(unnumbered-link-hop)
        |  |     |  |        |  +--rw unnumbered-link-hop
        |  |     |  |        |     +--rw link-tp-id    te-tp-id
        |  |     |  |        |     +--rw node-id       te-node-id
        |  |     |  |        |     +--rw hop-type?     te-hop-type
        |  |     |  |        |     +--rw direction?
        |  |     |  |        |             te-link-direction
        |  |     |  |        +--:(as-number)
        |  |     |  |        |  +--rw as-number-hop
        |  |     |  |        |     +--rw as-number    inet:as-number
        |  |     |  |        |     +--rw hop-type?    te-hop-type
        |  |     |  |        +--:(label)
        |  |     |  |           +--rw label-hop
        |  |     |  |              +--rw te-label
        |  |     |  |                 +--rw (technology)?
        |  |     |  |                 |  +--:(generic)
        |  |     |  |                 |     +--rw generic?
        |  |     |  |                 |             rt-
 types:generalized-label
        |  |     |  |                 +--rw direction?
        |  |     |  |                         te-label-direction
        |  |     |  +--rw protection-type?             identityref
        |  |     |  +--rw tunnel-termination-points
        |  |     |  |  +--rw source?        binary
        |  |     |  |  +--rw destination?   binary
        |  |     |  +--rw tunnels
        |  |     |     +--rw sharing?   boolean
        |  |     |     +--rw tunnel* [tunnel-name]
        |  |     |        +--rw tunnel-name    string
        |  |     |        +--rw sharing?       boolean
        |  |     +--rw path-constraints
        |  |     |  +--rw te-bandwidth
        |  |     |  |  +--rw (technology)?
        |  |     |  |     +--:(generic)
        |  |     |  |        +--rw generic?   te-bandwidth
        |  |     |  +--rw link-protection?          identityref
        |  |     |  +--rw setup-priority?           uint8
        |  |     |  +--rw hold-priority?            uint8
        |  |     |  +--rw signaling-type?           identityref
        |  |     |  +--rw path-metric-bounds
        |  |     |  |  +--rw path-metric-bound* [metric-type]
        |  |     |  |     +--rw metric-type    identityref
        |  |     |  |     +--rw upper-bound?   uint64
        |  |     |  +--rw path-affinities-values
        |  |     |  |  +--rw path-affinities-value* [usage]
        |  |     |  |     +--rw usage    identityref
        |  |     |  |     +--rw value?   admin-groups
        |  |     |  +--rw path-affinity-names
        |  |     |  |  +--rw path-affinity-name* [usage]
        |  |     |  |     +--rw usage            identityref
        |  |     |  |     +--rw affinity-name* [name]
        |  |     |  |        +--rw name    string
        |  |     |  +--rw path-srlgs-lists
        |  |     |  |  +--rw path-srlgs-list* [usage]
        |  |     |  |     +--rw usage     identityref
        |  |     |  |     +--rw values*   srlg
        |  |     |  +--rw path-srlgs-names
        |  |     |  |  +--rw path-srlgs-name* [usage]
        |  |     |  |     +--rw usage    identityref
        |  |     |  |     +--rw names*   string
        |  |     |  +--rw disjointness?
        |  |     |          te-path-disjointness
        |  |     +--rw optimizations
        |  |     |  +--rw (algorithm)?
        |  |     |     +--:(metric) {path-optimization-metric}?
        |  |     |     |  +--rw optimization-metric* [metric-type]
        |  |     |     |  |  +--rw metric-type
        |  |     |     |  |  |       identityref
        |  |     |     |  |  +--rw weight?
        |  |     |     |  |  |       uint8
        |  |     |     |  |  +--rw explicit-route-exclude-objects
        |  |     |     |  |  |  +--rw route-object-exclude-object*
        |  |     |     |  |  |          [index]
        |  |     |     |  |  |     +--rw index
        |  |     |     |  |  |     |       uint32
        |  |     |     |  |  |     +--rw (type)?
        |  |     |     |  |  |        +--:(numbered-node-hop)
        |  |     |     |  |  |        |  +--rw numbered-node-hop
        |  |     |     |  |  |        |     +--rw node-id
        |  |     |     |  |  |        |     |       te-node-id
        |  |     |     |  |  |        |     +--rw hop-type?
        |  |     |     |  |  |        |             te-hop-type
        |  |     |     |  |  |        +--:(numbered-link-hop)
        |  |     |     |  |  |        |  +--rw numbered-link-hop
        |  |     |     |  |  |        |     +--rw link-tp-id
        |  |     |     |  |  |        |     |       te-tp-id
        |  |     |     |  |  |        |     +--rw hop-type?
        |  |     |     |  |  |        |     |       te-hop-type
        |  |     |     |  |  |        |     +--rw direction?
        |  |     |     |  |  |        |             te-link-direction
        |  |     |     |  |  |        +--:(unnumbered-link-hop)
        |  |     |     |  |  |        |  +--rw unnumbered-link-hop
        |  |     |     |  |  |        |     +--rw link-tp-id
        |  |     |     |  |  |        |     |       te-tp-id
        |  |     |     |  |  |        |     +--rw node-id
        |  |     |     |  |  |        |     |       te-node-id
        |  |     |     |  |  |        |     +--rw hop-type?
        |  |     |     |  |  |        |     |       te-hop-type
        |  |     |     |  |  |        |     +--rw direction?
        |  |     |     |  |  |        |             te-link-direction
        |  |     |     |  |  |        +--:(as-number)
        |  |     |     |  |  |        |  +--rw as-number-hop
        |  |     |     |  |  |        |     +--rw as-number
        |  |     |     |  |  |        |     |       inet:as-number
        |  |     |     |  |  |        |     +--rw hop-type?
        |  |     |     |  |  |        |             te-hop-type
        |  |     |     |  |  |        +--:(label)
        |  |     |     |  |  |        |  +--rw label-hop
        |  |     |     |  |  |        |     +--rw te-label
        |  |     |     |  |  |        |        +--rw (technology)?
        |  |     |     |  |  |        |        |  +--:(generic)
        |  |     |     |  |  |        |        |     +--rw generic?
        |  |     |     |  |  |        |        |             rt-
 types:generalized-label
        |  |     |     |  |  |        |        +--rw direction?
        |  |     |     |  |  |        |                te-label-
 direction
        |  |     |     |  |  |        +--:(srlg)
        |  |     |     |  |  |           +--rw srlg
        |  |     |     |  |  |              +--rw srlg?   uint32
        |  |     |     |  |  +--rw explicit-route-include-objects
        |  |     |     |  |     +--rw route-object-include-object*
        |  |     |     |  |             [index]
        |  |     |     |  |        +--rw index
        |  |     |     |  |        |       uint32
        |  |     |     |  |        +--rw (type)?
        |  |     |     |  |           +--:(numbered-node-hop)
        |  |     |     |  |           |  +--rw numbered-node-hop
        |  |     |     |  |           |     +--rw node-id
        |  |     |     |  |           |     |       te-node-id
        |  |     |     |  |           |     +--rw hop-type?
        |  |     |     |  |           |             te-hop-type
        |  |     |     |  |           +--:(numbered-link-hop)
        |  |     |     |  |           |  +--rw numbered-link-hop
        |  |     |     |  |           |     +--rw link-tp-id
        |  |     |     |  |           |     |       te-tp-id
        |  |     |     |  |           |     +--rw hop-type?
        |  |     |     |  |           |     |       te-hop-type
        |  |     |     |  |           |     +--rw direction?
        |  |     |     |  |           |             te-link-direction
        |  |     |     |  |           +--:(unnumbered-link-hop)
        |  |     |     |  |           |  +--rw unnumbered-link-hop
        |  |     |     |  |           |     +--rw link-tp-id
        |  |     |     |  |           |     |       te-tp-id
        |  |     |     |  |           |     +--rw node-id
        |  |     |     |  |           |     |       te-node-id
        |  |     |     |  |           |     +--rw hop-type?
        |  |     |     |  |           |     |       te-hop-type
        |  |     |     |  |           |     +--rw direction?
        |  |     |     |  |           |             te-link-direction
        |  |     |     |  |           +--:(as-number)
        |  |     |     |  |           |  +--rw as-number-hop
        |  |     |     |  |           |     +--rw as-number
        |  |     |     |  |           |     |       inet:as-number
        |  |     |     |  |           |     +--rw hop-type?
        |  |     |     |  |           |             te-hop-type
        |  |     |     |  |           +--:(label)
        |  |     |     |  |              +--rw label-hop
        |  |     |     |  |                 +--rw te-label
        |  |     |     |  |                    +--rw (technology)?
        |  |     |     |  |                    |  +--:(generic)
        |  |     |     |  |                    |     +--rw generic?
        |  |     |     |  |                    |             rt-
 types:generalized-label
        |  |     |     |  |                    +--rw direction?
        |  |     |     |  |                            te-label-
 direction
        |  |     |     |  +--rw tiebreakers
        |  |     |     |     +--rw tiebreaker* [tiebreaker-type]
        |  |     |     |        +--rw tiebreaker-type    identityref
        |  |     |     +--:(objective-function)
        |  |     |              {path-optimization-objective-
 function}?
        |  |     |        +--rw objective-function
        |  |     |           +--rw objective-function-type?
        |  |     |                   identityref
        |  |     +--ro path-properties
        |  |        +--ro path-metric* [metric-type]
        |  |        |  +--ro metric-type           identityref
        |  |        |  +--ro accumulative-value?   uint64
        |  |        +--ro path-affinities-values
        |  |        |  +--ro path-affinities-value* [usage]
        |  |        |     +--ro usage    identityref
        |  |        |     +--ro value?   admin-groups
        |  |        +--ro path-affinity-names
        |  |        |  +--ro path-affinity-name* [usage]
        |  |        |     +--ro usage            identityref
        |  |        |     +--ro affinity-name* [name]
        |  |        |        +--ro name    string
        |  |        +--ro path-srlgs-lists
        |  |        |  +--ro path-srlgs-list* [usage]
        |  |        |     +--ro usage     identityref
        |  |        |     +--ro values*   srlg
        |  |        +--ro path-srlgs-names
        |  |        |  +--ro path-srlgs-name* [usage]
        |  |        |     +--ro usage    identityref
        |  |        |     +--ro names*   string
        |  |        +--ro path-route-objects
        |  |           +--ro path-route-object* [index]
        |  |              +--ro index                        uint32
        |  |              +--ro (type)?
        |  |                 +--:(numbered-node-hop)
        |  |                 |  +--ro numbered-node-hop
        |  |                 |     +--ro node-id     te-node-id
        |  |                 |     +--ro hop-type?   te-hop-type
        |  |                 +--:(numbered-link-hop)
        |  |                 |  +--ro numbered-link-hop
        |  |                 |     +--ro link-tp-id    te-tp-id
        |  |                 |     +--ro hop-type?     te-hop-type
        |  |                 |     +--ro direction?
        |  |                 |             te-link-direction
        |  |                 +--:(unnumbered-link-hop)
        |  |                 |  +--ro unnumbered-link-hop
        |  |                 |     +--ro link-tp-id    te-tp-id
        |  |                 |     +--ro node-id       te-node-id
        |  |                 |     +--ro hop-type?     te-hop-type
        |  |                 |     +--ro direction?
        |  |                 |             te-link-direction
        |  |                 +--:(as-number)
        |  |                 |  +--ro as-number-hop
        |  |                 |     +--ro as-number    inet:as-number
        |  |                 |     +--ro hop-type?    te-hop-type
        |  |                 +--:(label)
        |  |                    +--ro label-hop
        |  |                       +--ro te-label
        |  |                          +--ro (technology)?
        |  |                          |  +--:(generic)
        |  |                          |     +--ro generic?
        |  |                          |             rt-
 types:generalized-label
        |  |                          +--ro direction?
        |  |                                  te-label-direction
        |  +--rw domain-id?               uint32
        |  +--rw is-abstract?             empty
        |  +--rw name?                    string
        |  +--rw signaling-address*       inet:ip-address
        |  +--rw underlay-topology {te-topology-hierarchy}?
        |     +--rw network-ref?   -> /nw:networks/network/network-id
        +--ro oper-status?                   te-types:te-oper-status
        +--ro geolocation
        |  +--ro altitude?    int64
        |  +--ro latitude?    geographic-coordinate-degree
        |  +--ro longitude?   geographic-coordinate-degree
        +--ro is-multi-access-dr?            empty
        +--ro information-source?            te-info-source
        +--ro information-source-instance?   string
        +--ro information-source-state
        |  +--ro credibility-preference?    uint16
        |  +--ro logical-network-element?   string
        |  +--ro network-instance?          string
        |  +--ro topology
        |     +--ro node-ref?      leafref
        |     +--ro network-ref?   -> /nw:networks/network/network-id
        +--ro information-source-entry*
        |       [information-source information-source-instance]
        |  +--ro information-source             te-info-source
        |  +--ro information-source-instance    string
        |  +--ro information-source-state
        |  |  +--ro credibility-preference?    uint16
        |  |  +--ro logical-network-element?   string
        |  |  +--ro network-instance?          string
        |  |  +--ro topology
        |  |     +--ro node-ref?      leafref
        |  |     +--ro network-ref?
        |  |             -> /nw:networks/network/network-id
        |  +--ro connectivity-matrices
        |  |  +--ro number-of-entries?     uint16
        |  |  +--ro label-restrictions
        |  |  |  +--ro label-restriction* [index]
        |  |  |     +--ro restriction?    enumeration
        |  |  |     +--ro index           uint32
        |  |  |     +--ro label-start
        |  |  |     |  +--ro te-label
        |  |  |     |     +--ro (technology)?
        |  |  |     |     |  +--:(generic)
        |  |  |     |     |     +--ro generic?
        |  |  |     |     |             rt-types:generalized-label
        |  |  |     |     +--ro direction?       te-label-direction
        |  |  |     +--ro label-end
        |  |  |     |  +--ro te-label
        |  |  |     |     +--ro (technology)?
        |  |  |     |     |  +--:(generic)
        |  |  |     |     |     +--ro generic?
        |  |  |     |     |             rt-types:generalized-label
        |  |  |     |     +--ro direction?       te-label-direction
        |  |  |     +--ro label-step
        |  |  |     |  +--ro (technology)?
        |  |  |     |     +--:(generic)
        |  |  |     |        +--ro generic?   int32
        |  |  |     +--ro range-bitmap?   yang:hex-string
        |  |  +--ro is-allowed?            boolean
        |  |  +--ro underlay {te-topology-hierarchy}?
        |  |  |  +--ro enabled?                     boolean
        |  |  |  +--ro primary-path
        |  |  |  |  +--ro network-ref?
        |  |  |  |  |       -> /nw:networks/network/network-id
        |  |  |  |  +--ro path-element* [path-element-id]
        |  |  |  |     +--ro path-element-id              uint32
        |  |  |  |     +--ro (type)?
        |  |  |  |        +--:(numbered-node-hop)
        |  |  |  |        |  +--ro numbered-node-hop
        |  |  |  |        |     +--ro node-id     te-node-id
        |  |  |  |        |     +--ro hop-type?   te-hop-type
        |  |  |  |        +--:(numbered-link-hop)
        |  |  |  |        |  +--ro numbered-link-hop
        |  |  |  |        |     +--ro link-tp-id    te-tp-id
        |  |  |  |        |     +--ro hop-type?     te-hop-type
        |  |  |  |        |     +--ro direction?    te-link-direction
        |  |  |  |        +--:(unnumbered-link-hop)
        |  |  |  |        |  +--ro unnumbered-link-hop
        |  |  |  |        |     +--ro link-tp-id    te-tp-id
        |  |  |  |        |     +--ro node-id       te-node-id
        |  |  |  |        |     +--ro hop-type?     te-hop-type
        |  |  |  |        |     +--ro direction?    te-link-direction
        |  |  |  |        +--:(as-number)
        |  |  |  |        |  +--ro as-number-hop
        |  |  |  |        |     +--ro as-number    inet:as-number
        |  |  |  |        |     +--ro hop-type?    te-hop-type
        |  |  |  |        +--:(label)
        |  |  |  |           +--ro label-hop
        |  |  |  |              +--ro te-label
        |  |  |  |                 +--ro (technology)?
        |  |  |  |                 |  +--:(generic)
        |  |  |  |                 |     +--ro generic?
        |  |  |  |                 |             rt-types:generalized-
 label
        |  |  |  |                 +--ro direction?
        |  |  |  |                         te-label-direction
        |  |  |  +--ro backup-path* [index]
        |  |  |  |  +--ro index           uint32
        |  |  |  |  +--ro network-ref?
        |  |  |  |  |       -> /nw:networks/network/network-id
        |  |  |  |  +--ro path-element* [path-element-id]
        |  |  |  |     +--ro path-element-id              uint32
        |  |  |  |     +--ro (type)?
        |  |  |  |        +--:(numbered-node-hop)
        |  |  |  |        |  +--ro numbered-node-hop
        |  |  |  |        |     +--ro node-id     te-node-id
        |  |  |  |        |     +--ro hop-type?   te-hop-type
        |  |  |  |        +--:(numbered-link-hop)
        |  |  |  |        |  +--ro numbered-link-hop
        |  |  |  |        |     +--ro link-tp-id    te-tp-id
        |  |  |  |        |     +--ro hop-type?     te-hop-type
        |  |  |  |        |     +--ro direction?    te-link-direction
        |  |  |  |        +--:(unnumbered-link-hop)
        |  |  |  |        |  +--ro unnumbered-link-hop
        |  |  |  |        |     +--ro link-tp-id    te-tp-id
        |  |  |  |        |     +--ro node-id       te-node-id
        |  |  |  |        |     +--ro hop-type?     te-hop-type
        |  |  |  |        |     +--ro direction?    te-link-direction
        |  |  |  |        +--:(as-number)
        |  |  |  |        |  +--ro as-number-hop
        |  |  |  |        |     +--ro as-number    inet:as-number
        |  |  |  |        |     +--ro hop-type?    te-hop-type
        |  |  |  |        +--:(label)
        |  |  |  |           +--ro label-hop
        |  |  |  |              +--ro te-label
        |  |  |  |                 +--ro (technology)?
        |  |  |  |                 |  +--:(generic)
        |  |  |  |                 |     +--ro generic?
        |  |  |  |                 |             rt-types:generalized-
 label
        |  |  |  |                 +--ro direction?
        |  |  |  |                         te-label-direction
        |  |  |  +--ro protection-type?             identityref
        |  |  |  +--ro tunnel-termination-points
        |  |  |  |  +--ro source?        binary
        |  |  |  |  +--ro destination?   binary
        |  |  |  +--ro tunnels
        |  |  |     +--ro sharing?   boolean
        |  |  |     +--ro tunnel* [tunnel-name]
        |  |  |        +--ro tunnel-name    string
        |  |  |        +--ro sharing?       boolean
        |  |  +--ro path-constraints
        |  |  |  +--ro te-bandwidth
        |  |  |  |  +--ro (technology)?
        |  |  |  |     +--:(generic)
        |  |  |  |        +--ro generic?   te-bandwidth
        |  |  |  +--ro link-protection?          identityref
        |  |  |  +--ro setup-priority?           uint8
        |  |  |  +--ro hold-priority?            uint8
        |  |  |  +--ro signaling-type?           identityref
        |  |  |  +--ro path-metric-bounds
        |  |  |  |  +--ro path-metric-bound* [metric-type]
        |  |  |  |     +--ro metric-type    identityref
        |  |  |  |     +--ro upper-bound?   uint64
        |  |  |  +--ro path-affinities-values
        |  |  |  |  +--ro path-affinities-value* [usage]
        |  |  |  |     +--ro usage    identityref
        |  |  |  |     +--ro value?   admin-groups
        |  |  |  +--ro path-affinity-names
        |  |  |  |  +--ro path-affinity-name* [usage]
        |  |  |  |     +--ro usage            identityref
        |  |  |  |     +--ro affinity-name* [name]
        |  |  |  |        +--ro name    string
        |  |  |  +--ro path-srlgs-lists
        |  |  |  |  +--ro path-srlgs-list* [usage]
        |  |  |  |     +--ro usage     identityref
        |  |  |  |     +--ro values*   srlg
        |  |  |  +--ro path-srlgs-names
        |  |  |  |  +--ro path-srlgs-name* [usage]
        |  |  |  |     +--ro usage    identityref
        |  |  |  |     +--ro names*   string
        |  |  |  +--ro disjointness?             te-path-disjointness
        |  |  +--ro optimizations
        |  |  |  +--ro (algorithm)?
        |  |  |     +--:(metric) {path-optimization-metric}?
        |  |  |     |  +--ro optimization-metric* [metric-type]
        |  |  |     |  |  +--ro metric-type
        |  |  |     |  |  |       identityref
        |  |  |     |  |  +--ro weight?
        |  |  |     |  |  |       uint8
        |  |  |     |  |  +--ro explicit-route-exclude-objects
        |  |  |     |  |  |  +--ro route-object-exclude-object*
        |  |  |     |  |  |          [index]
        |  |  |     |  |  |     +--ro index
        |  |  |     |  |  |     |       uint32
        |  |  |     |  |  |     +--ro (type)?
        |  |  |     |  |  |        +--:(numbered-node-hop)
        |  |  |     |  |  |        |  +--ro numbered-node-hop
        |  |  |     |  |  |        |     +--ro node-id     te-node-id
        |  |  |     |  |  |        |     +--ro hop-type?   te-hop-type
        |  |  |     |  |  |        +--:(numbered-link-hop)
        |  |  |     |  |  |        |  +--ro numbered-link-hop
        |  |  |     |  |  |        |     +--ro link-tp-id    te-tp-id
        |  |  |     |  |  |        |     +--ro hop-type?
        |  |  |     |  |  |        |     |       te-hop-type
        |  |  |     |  |  |        |     +--ro direction?
        |  |  |     |  |  |        |             te-link-direction
        |  |  |     |  |  |        +--:(unnumbered-link-hop)
        |  |  |     |  |  |        |  +--ro unnumbered-link-hop
        |  |  |     |  |  |        |     +--ro link-tp-id    te-tp-id
        |  |  |     |  |  |        |     +--ro node-id
        |  |  |     |  |  |        |     |       te-node-id
        |  |  |     |  |  |        |     +--ro hop-type?
        |  |  |     |  |  |        |     |       te-hop-type
        |  |  |     |  |  |        |     +--ro direction?
        |  |  |     |  |  |        |             te-link-direction
        |  |  |     |  |  |        +--:(as-number)
        |  |  |     |  |  |        |  +--ro as-number-hop
        |  |  |     |  |  |        |     +--ro as-number
        |  |  |     |  |  |        |     |       inet:as-number
        |  |  |     |  |  |        |     +--ro hop-type?
        |  |  |     |  |  |        |             te-hop-type
        |  |  |     |  |  |        +--:(label)
        |  |  |     |  |  |        |  +--ro label-hop
        |  |  |     |  |  |        |     +--ro te-label
        |  |  |     |  |  |        |        +--ro (technology)?
        |  |  |     |  |  |        |        |  +--:(generic)
        |  |  |     |  |  |        |        |     +--ro generic?
        |  |  |     |  |  |        |        |             rt-
 types:generalized-label
        |  |  |     |  |  |        |        +--ro direction?
        |  |  |     |  |  |        |                te-label-direction
        |  |  |     |  |  |        +--:(srlg)
        |  |  |     |  |  |           +--ro srlg
        |  |  |     |  |  |              +--ro srlg?   uint32
        |  |  |     |  |  +--ro explicit-route-include-objects
        |  |  |     |  |     +--ro route-object-include-object*
        |  |  |     |  |             [index]
        |  |  |     |  |        +--ro index
        |  |  |     |  |        |       uint32
        |  |  |     |  |        +--ro (type)?
        |  |  |     |  |           +--:(numbered-node-hop)
        |  |  |     |  |           |  +--ro numbered-node-hop
        |  |  |     |  |           |     +--ro node-id     te-node-id
        |  |  |     |  |           |     +--ro hop-type?   te-hop-type
        |  |  |     |  |           +--:(numbered-link-hop)
        |  |  |     |  |           |  +--ro numbered-link-hop
        |  |  |     |  |           |     +--ro link-tp-id    te-tp-id
        |  |  |     |  |           |     +--ro hop-type?
        |  |  |     |  |           |     |       te-hop-type
        |  |  |     |  |           |     +--ro direction?
        |  |  |     |  |           |             te-link-direction
        |  |  |     |  |           +--:(unnumbered-link-hop)
        |  |  |     |  |           |  +--ro unnumbered-link-hop
        |  |  |     |  |           |     +--ro link-tp-id    te-tp-id
        |  |  |     |  |           |     +--ro node-id
        |  |  |     |  |           |     |       te-node-id
        |  |  |     |  |           |     +--ro hop-type?
        |  |  |     |  |           |     |       te-hop-type
        |  |  |     |  |           |     +--ro direction?
        |  |  |     |  |           |             te-link-direction
        |  |  |     |  |           +--:(as-number)
        |  |  |     |  |           |  +--ro as-number-hop
        |  |  |     |  |           |     +--ro as-number
        |  |  |     |  |           |     |       inet:as-number
        |  |  |     |  |           |     +--ro hop-type?
        |  |  |     |  |           |             te-hop-type
        |  |  |     |  |           +--:(label)
        |  |  |     |  |              +--ro label-hop
        |  |  |     |  |                 +--ro te-label
        |  |  |     |  |                    +--ro (technology)?
        |  |  |     |  |                    |  +--:(generic)
        |  |  |     |  |                    |     +--ro generic?
        |  |  |     |  |                    |             rt-
 types:generalized-label
        |  |  |     |  |                    +--ro direction?
        |  |  |     |  |                            te-label-direction
        |  |  |     |  +--ro tiebreakers
        |  |  |     |     +--ro tiebreaker* [tiebreaker-type]
        |  |  |     |        +--ro tiebreaker-type    identityref
        |  |  |     +--:(objective-function)
        |  |  |              {path-optimization-objective-function}?
        |  |  |        +--ro objective-function
        |  |  |           +--ro objective-function-type?   identityref
        |  |  +--ro path-properties
        |  |  |  +--ro path-metric* [metric-type]
        |  |  |  |  +--ro metric-type           identityref
        |  |  |  |  +--ro accumulative-value?   uint64
        |  |  |  +--ro path-affinities-values
        |  |  |  |  +--ro path-affinities-value* [usage]
        |  |  |  |     +--ro usage    identityref
        |  |  |  |     +--ro value?   admin-groups
        |  |  |  +--ro path-affinity-names
        |  |  |  |  +--ro path-affinity-name* [usage]
        |  |  |  |     +--ro usage            identityref
        |  |  |  |     +--ro affinity-name* [name]
        |  |  |  |        +--ro name    string
        |  |  |  +--ro path-srlgs-lists
        |  |  |  |  +--ro path-srlgs-list* [usage]
        |  |  |  |     +--ro usage     identityref
        |  |  |  |     +--ro values*   srlg
        |  |  |  +--ro path-srlgs-names
        |  |  |  |  +--ro path-srlgs-name* [usage]
        |  |  |  |     +--ro usage    identityref
        |  |  |  |     +--ro names*   string
        |  |  |  +--ro path-route-objects
        |  |  |     +--ro path-route-object* [index]
        |  |  |        +--ro index                        uint32
        |  |  |        +--ro (type)?
        |  |  |           +--:(numbered-node-hop)
        |  |  |           |  +--ro numbered-node-hop
        |  |  |           |     +--ro node-id     te-node-id
        |  |  |           |     +--ro hop-type?   te-hop-type
        |  |  |           +--:(numbered-link-hop)
        |  |  |           |  +--ro numbered-link-hop
        |  |  |           |     +--ro link-tp-id    te-tp-id
        |  |  |           |     +--ro hop-type?     te-hop-type
        |  |  |           |     +--ro direction?    te-link-direction
        |  |  |           +--:(unnumbered-link-hop)
        |  |  |           |  +--ro unnumbered-link-hop
        |  |  |           |     +--ro link-tp-id    te-tp-id
        |  |  |           |     +--ro node-id       te-node-id
        |  |  |           |     +--ro hop-type?     te-hop-type
        |  |  |           |     +--ro direction?    te-link-direction
        |  |  |           +--:(as-number)
        |  |  |           |  +--ro as-number-hop
        |  |  |           |     +--ro as-number    inet:as-number
        |  |  |           |     +--ro hop-type?    te-hop-type
        |  |  |           +--:(label)
        |  |  |              +--ro label-hop
        |  |  |                 +--ro te-label
        |  |  |                    +--ro (technology)?
        |  |  |                    |  +--:(generic)
        |  |  |                    |     +--ro generic?
        |  |  |                    |             rt-types:generalized-
 label
        |  |  |                    +--ro direction?
        |  |  |                            te-label-direction
        |  |  +--ro connectivity-matrix* [id]
        |  |     +--ro id                  uint32
        |  |     +--ro from
        |  |     |  +--ro tp-ref?               leafref
        |  |     |  +--ro label-restrictions
        |  |     |     +--ro label-restriction* [index]
        |  |     |        +--ro restriction?    enumeration
        |  |     |        +--ro index           uint32
        |  |     |        +--ro label-start
        |  |     |        |  +--ro te-label
        |  |     |        |     +--ro (technology)?
        |  |     |        |     |  +--:(generic)
        |  |     |        |     |     +--ro generic?
        |  |     |        |     |             rt-types:generalized-
 label
        |  |     |        |     +--ro direction?
        |  |     |        |             te-label-direction
        |  |     |        +--ro label-end
        |  |     |        |  +--ro te-label
        |  |     |        |     +--ro (technology)?
        |  |     |        |     |  +--:(generic)
        |  |     |        |     |     +--ro generic?
        |  |     |        |     |             rt-types:generalized-
 label
        |  |     |        |     +--ro direction?
        |  |     |        |             te-label-direction
        |  |     |        +--ro label-step
        |  |     |        |  +--ro (technology)?
        |  |     |        |     +--:(generic)
        |  |     |        |        +--ro generic?   int32
        |  |     |        +--ro range-bitmap?   yang:hex-string
        |  |     +--ro to
        |  |     |  +--ro tp-ref?               leafref
        |  |     |  +--ro label-restrictions
        |  |     |     +--ro label-restriction* [index]
        |  |     |        +--ro restriction?    enumeration
        |  |     |        +--ro index           uint32
        |  |     |        +--ro label-start
        |  |     |        |  +--ro te-label
        |  |     |        |     +--ro (technology)?
        |  |     |        |     |  +--:(generic)
        |  |     |        |     |     +--ro generic?
        |  |     |        |     |             rt-types:generalized-
 label
        |  |     |        |     +--ro direction?
        |  |     |        |             te-label-direction
        |  |     |        +--ro label-end
        |  |     |        |  +--ro te-label
        |  |     |        |     +--ro (technology)?
        |  |     |        |     |  +--:(generic)
        |  |     |        |     |     +--ro generic?
        |  |     |        |     |             rt-types:generalized-
 label
        |  |     |        |     +--ro direction?
        |  |     |        |             te-label-direction
        |  |     |        +--ro label-step
        |  |     |        |  +--ro (technology)?
        |  |     |        |     +--:(generic)
        |  |     |        |        +--ro generic?   int32
        |  |     |        +--ro range-bitmap?   yang:hex-string
        |  |     +--ro is-allowed?         boolean
        |  |     +--ro underlay {te-topology-hierarchy}?
        |  |     |  +--ro enabled?                     boolean
        |  |     |  +--ro primary-path
        |  |     |  |  +--ro network-ref?
        |  |     |  |  |       -> /nw:networks/network/network-id
        |  |     |  |  +--ro path-element* [path-element-id]
        |  |     |  |     +--ro path-element-id              uint32
        |  |     |  |     +--ro (type)?
        |  |     |  |        +--:(numbered-node-hop)
        |  |     |  |        |  +--ro numbered-node-hop
        |  |     |  |        |     +--ro node-id     te-node-id
        |  |     |  |        |     +--ro hop-type?   te-hop-type
        |  |     |  |        +--:(numbered-link-hop)
        |  |     |  |        |  +--ro numbered-link-hop
        |  |     |  |        |     +--ro link-tp-id    te-tp-id
        |  |     |  |        |     +--ro hop-type?     te-hop-type
        |  |     |  |        |     +--ro direction?
        |  |     |  |        |             te-link-direction
        |  |     |  |        +--:(unnumbered-link-hop)
        |  |     |  |        |  +--ro unnumbered-link-hop
        |  |     |  |        |     +--ro link-tp-id    te-tp-id
        |  |     |  |        |     +--ro node-id       te-node-id
        |  |     |  |        |     +--ro hop-type?     te-hop-type
        |  |     |  |        |     +--ro direction?
        |  |     |  |        |             te-link-direction
        |  |     |  |        +--:(as-number)
        |  |     |  |        |  +--ro as-number-hop
        |  |     |  |        |     +--ro as-number    inet:as-number
        |  |     |  |        |     +--ro hop-type?    te-hop-type
        |  |     |  |        +--:(label)
        |  |     |  |           +--ro label-hop
        |  |     |  |              +--ro te-label
        |  |     |  |                 +--ro (technology)?
        |  |     |  |                 |  +--:(generic)
        |  |     |  |                 |     +--ro generic?
        |  |     |  |                 |             rt-
 types:generalized-label
        |  |     |  |                 +--ro direction?
        |  |     |  |                         te-label-direction
        |  |     |  +--ro backup-path* [index]
        |  |     |  |  +--ro index           uint32
        |  |     |  |  +--ro network-ref?
        |  |     |  |  |       -> /nw:networks/network/network-id
        |  |     |  |  +--ro path-element* [path-element-id]
        |  |     |  |     +--ro path-element-id              uint32
        |  |     |  |     +--ro (type)?
        |  |     |  |        +--:(numbered-node-hop)
        |  |     |  |        |  +--ro numbered-node-hop
        |  |     |  |        |     +--ro node-id     te-node-id
        |  |     |  |        |     +--ro hop-type?   te-hop-type
        |  |     |  |        +--:(numbered-link-hop)
        |  |     |  |        |  +--ro numbered-link-hop
        |  |     |  |        |     +--ro link-tp-id    te-tp-id
        |  |     |  |        |     +--ro hop-type?     te-hop-type
        |  |     |  |        |     +--ro direction?
        |  |     |  |        |             te-link-direction
        |  |     |  |        +--:(unnumbered-link-hop)
        |  |     |  |        |  +--ro unnumbered-link-hop
        |  |     |  |        |     +--ro link-tp-id    te-tp-id
        |  |     |  |        |     +--ro node-id       te-node-id
        |  |     |  |        |     +--ro hop-type?     te-hop-type
        |  |     |  |        |     +--ro direction?
        |  |     |  |        |             te-link-direction
        |  |     |  |        +--:(as-number)
        |  |     |  |        |  +--ro as-number-hop
        |  |     |  |        |     +--ro as-number    inet:as-number
        |  |     |  |        |     +--ro hop-type?    te-hop-type
        |  |     |  |        +--:(label)
        |  |     |  |           +--ro label-hop
        |  |     |  |              +--ro te-label
        |  |     |  |                 +--ro (technology)?
        |  |     |  |                 |  +--:(generic)
        |  |     |  |                 |     +--ro generic?
        |  |     |  |                 |             rt-
 types:generalized-label
        |  |     |  |                 +--ro direction?
        |  |     |  |                         te-label-direction
        |  |     |  +--ro protection-type?             identityref
        |  |     |  +--ro tunnel-termination-points
        |  |     |  |  +--ro source?        binary
        |  |     |  |  +--ro destination?   binary
        |  |     |  +--ro tunnels
        |  |     |     +--ro sharing?   boolean
        |  |     |     +--ro tunnel* [tunnel-name]
        |  |     |        +--ro tunnel-name    string
        |  |     |        +--ro sharing?       boolean
        |  |     +--ro path-constraints
        |  |     |  +--ro te-bandwidth
        |  |     |  |  +--ro (technology)?
        |  |     |  |     +--:(generic)
        |  |     |  |        +--ro generic?   te-bandwidth
        |  |     |  +--ro link-protection?          identityref
        |  |     |  +--ro setup-priority?           uint8
        |  |     |  +--ro hold-priority?            uint8
        |  |     |  +--ro signaling-type?           identityref
        |  |     |  +--ro path-metric-bounds
        |  |     |  |  +--ro path-metric-bound* [metric-type]
        |  |     |  |     +--ro metric-type    identityref
        |  |     |  |     +--ro upper-bound?   uint64
        |  |     |  +--ro path-affinities-values
        |  |     |  |  +--ro path-affinities-value* [usage]
        |  |     |  |     +--ro usage    identityref
        |  |     |  |     +--ro value?   admin-groups
        |  |     |  +--ro path-affinity-names
        |  |     |  |  +--ro path-affinity-name* [usage]
        |  |     |  |     +--ro usage            identityref
        |  |     |  |     +--ro affinity-name* [name]
        |  |     |  |        +--ro name    string
        |  |     |  +--ro path-srlgs-lists
        |  |     |  |  +--ro path-srlgs-list* [usage]
        |  |     |  |     +--ro usage     identityref
        |  |     |  |     +--ro values*   srlg
        |  |     |  +--ro path-srlgs-names
        |  |     |  |  +--ro path-srlgs-name* [usage]
        |  |     |  |     +--ro usage    identityref
        |  |     |  |     +--ro names*   string
        |  |     |  +--ro disjointness?
        |  |     |          te-path-disjointness
        |  |     +--ro optimizations
        |  |     |  +--ro (algorithm)?
        |  |     |     +--:(metric) {path-optimization-metric}?
        |  |     |     |  +--ro optimization-metric* [metric-type]
        |  |     |     |  |  +--ro metric-type
        |  |     |     |  |  |       identityref
        |  |     |     |  |  +--ro weight?
        |  |     |     |  |  |       uint8
        |  |     |     |  |  +--ro explicit-route-exclude-objects
        |  |     |     |  |  |  +--ro route-object-exclude-object*
        |  |     |     |  |  |          [index]
        |  |     |     |  |  |     +--ro index
        |  |     |     |  |  |     |       uint32
        |  |     |     |  |  |     +--ro (type)?
        |  |     |     |  |  |        +--:(numbered-node-hop)
        |  |     |     |  |  |        |  +--ro numbered-node-hop
        |  |     |     |  |  |        |     +--ro node-id
        |  |     |     |  |  |        |     |       te-node-id
        |  |     |     |  |  |        |     +--ro hop-type?
        |  |     |     |  |  |        |             te-hop-type
        |  |     |     |  |  |        +--:(numbered-link-hop)
        |  |     |     |  |  |        |  +--ro numbered-link-hop
        |  |     |     |  |  |        |     +--ro link-tp-id
        |  |     |     |  |  |        |     |       te-tp-id
        |  |     |     |  |  |        |     +--ro hop-type?
        |  |     |     |  |  |        |     |       te-hop-type
        |  |     |     |  |  |        |     +--ro direction?
        |  |     |     |  |  |        |             te-link-direction
        |  |     |     |  |  |        +--:(unnumbered-link-hop)
        |  |     |     |  |  |        |  +--ro unnumbered-link-hop
        |  |     |     |  |  |        |     +--ro link-tp-id
        |  |     |     |  |  |        |     |       te-tp-id
        |  |     |     |  |  |        |     +--ro node-id
        |  |     |     |  |  |        |     |       te-node-id
        |  |     |     |  |  |        |     +--ro hop-type?
        |  |     |     |  |  |        |     |       te-hop-type
        |  |     |     |  |  |        |     +--ro direction?
        |  |     |     |  |  |        |             te-link-direction
        |  |     |     |  |  |        +--:(as-number)
        |  |     |     |  |  |        |  +--ro as-number-hop
        |  |     |     |  |  |        |     +--ro as-number
        |  |     |     |  |  |        |     |       inet:as-number
        |  |     |     |  |  |        |     +--ro hop-type?
        |  |     |     |  |  |        |             te-hop-type
        |  |     |     |  |  |        +--:(label)
        |  |     |     |  |  |        |  +--ro label-hop
        |  |     |     |  |  |        |     +--ro te-label
        |  |     |     |  |  |        |        +--ro (technology)?
        |  |     |     |  |  |        |        |  +--:(generic)
        |  |     |     |  |  |        |        |     +--ro generic?
        |  |     |     |  |  |        |        |             rt-
 types:generalized-label
        |  |     |     |  |  |        |        +--ro direction?
        |  |     |     |  |  |        |                te-label-
 direction
        |  |     |     |  |  |        +--:(srlg)
        |  |     |     |  |  |           +--ro srlg
        |  |     |     |  |  |              +--ro srlg?   uint32
        |  |     |     |  |  +--ro explicit-route-include-objects
        |  |     |     |  |     +--ro route-object-include-object*
        |  |     |     |  |             [index]
        |  |     |     |  |        +--ro index
        |  |     |     |  |        |       uint32
        |  |     |     |  |        +--ro (type)?
        |  |     |     |  |           +--:(numbered-node-hop)
        |  |     |     |  |           |  +--ro numbered-node-hop
        |  |     |     |  |           |     +--ro node-id
        |  |     |     |  |           |     |       te-node-id
        |  |     |     |  |           |     +--ro hop-type?
        |  |     |     |  |           |             te-hop-type
        |  |     |     |  |           +--:(numbered-link-hop)
        |  |     |     |  |           |  +--ro numbered-link-hop
        |  |     |     |  |           |     +--ro link-tp-id
        |  |     |     |  |           |     |       te-tp-id
        |  |     |     |  |           |     +--ro hop-type?
        |  |     |     |  |           |     |       te-hop-type
        |  |     |     |  |           |     +--ro direction?
        |  |     |     |  |           |             te-link-direction
        |  |     |     |  |           +--:(unnumbered-link-hop)
        |  |     |     |  |           |  +--ro unnumbered-link-hop
        |  |     |     |  |           |     +--ro link-tp-id
        |  |     |     |  |           |     |       te-tp-id
        |  |     |     |  |           |     +--ro node-id
        |  |     |     |  |           |     |       te-node-id
        |  |     |     |  |           |     +--ro hop-type?
        |  |     |     |  |           |     |       te-hop-type
        |  |     |     |  |           |     +--ro direction?
        |  |     |     |  |           |             te-link-direction
        |  |     |     |  |           +--:(as-number)
        |  |     |     |  |           |  +--ro as-number-hop
        |  |     |     |  |           |     +--ro as-number
        |  |     |     |  |           |     |       inet:as-number
        |  |     |     |  |           |     +--ro hop-type?
        |  |     |     |  |           |             te-hop-type
        |  |     |     |  |           +--:(label)
        |  |     |     |  |              +--ro label-hop
        |  |     |     |  |                 +--ro te-label
        |  |     |     |  |                    +--ro (technology)?
        |  |     |     |  |                    |  +--:(generic)
        |  |     |     |  |                    |     +--ro generic?
        |  |     |     |  |                    |             rt-
 types:generalized-label
        |  |     |     |  |                    +--ro direction?
        |  |     |     |  |                            te-label-
 direction
        |  |     |     |  +--ro tiebreakers
        |  |     |     |     +--ro tiebreaker* [tiebreaker-type]
        |  |     |     |        +--ro tiebreaker-type    identityref
        |  |     |     +--:(objective-function)
        |  |     |              {path-optimization-objective-
 function}?
        |  |     |        +--ro objective-function
        |  |     |           +--ro objective-function-type?
        |  |     |                   identityref
        |  |     +--ro path-properties
        |  |        +--ro path-metric* [metric-type]
        |  |        |  +--ro metric-type           identityref
        |  |        |  +--ro accumulative-value?   uint64
        |  |        +--ro path-affinities-values
        |  |        |  +--ro path-affinities-value* [usage]
        |  |        |     +--ro usage    identityref
        |  |        |     +--ro value?   admin-groups
        |  |        +--ro path-affinity-names
        |  |        |  +--ro path-affinity-name* [usage]
        |  |        |     +--ro usage            identityref
        |  |        |     +--ro affinity-name* [name]
        |  |        |        +--ro name    string
        |  |        +--ro path-srlgs-lists
        |  |        |  +--ro path-srlgs-list* [usage]
        |  |        |     +--ro usage     identityref
        |  |        |     +--ro values*   srlg
        |  |        +--ro path-srlgs-names
        |  |        |  +--ro path-srlgs-name* [usage]
        |  |        |     +--ro usage    identityref
        |  |        |     +--ro names*   string
        |  |        +--ro path-route-objects
        |  |           +--ro path-route-object* [index]
        |  |              +--ro index                        uint32
        |  |              +--ro (type)?
        |  |                 +--:(numbered-node-hop)
        |  |                 |  +--ro numbered-node-hop
        |  |                 |     +--ro node-id     te-node-id
        |  |                 |     +--ro hop-type?   te-hop-type
        |  |                 +--:(numbered-link-hop)
        |  |                 |  +--ro numbered-link-hop
        |  |                 |     +--ro link-tp-id    te-tp-id
        |  |                 |     +--ro hop-type?     te-hop-type
        |  |                 |     +--ro direction?
        |  |                 |             te-link-direction
        |  |                 +--:(unnumbered-link-hop)
        |  |                 |  +--ro unnumbered-link-hop
        |  |                 |     +--ro link-tp-id    te-tp-id
        |  |                 |     +--ro node-id       te-node-id
        |  |                 |     +--ro hop-type?     te-hop-type
        |  |                 |     +--ro direction?
        |  |                 |             te-link-direction
        |  |                 +--:(as-number)
        |  |                 |  +--ro as-number-hop
        |  |                 |     +--ro as-number    inet:as-number
        |  |                 |     +--ro hop-type?    te-hop-type
        |  |                 +--:(label)
        |  |                    +--ro label-hop
        |  |                       +--ro te-label
        |  |                          +--ro (technology)?
        |  |                          |  +--:(generic)
        |  |                          |     +--ro generic?
        |  |                          |             rt-
 types:generalized-label
        |  |                          +--ro direction?
        |  |                                  te-label-direction
        |  +--ro domain-id?                     uint32
        |  +--ro is-abstract?                   empty
        |  +--ro name?                          string
        |  +--ro signaling-address*             inet:ip-address
        |  +--ro underlay-topology {te-topology-hierarchy}?
        |     +--ro network-ref?   -> /nw:networks/network/network-id
        +--ro statistics
        |  +--ro discontinuity-time?          yang:date-and-time
        |  +--ro node
        |  |  +--ro disables?             yang:counter32
        |  |  +--ro enables?              yang:counter32
        |  |  +--ro maintenance-sets?     yang:counter32
        |  |  +--ro maintenance-clears?   yang:counter32
        |  |  +--ro modifies?             yang:counter32
        |  +--ro connectivity-matrix-entry
        |     +--ro creates?    yang:counter32
        |     +--ro deletes?    yang:counter32
        |     +--ro disables?   yang:counter32
        |     +--ro enables?    yang:counter32
        |     +--ro modifies?   yang:counter32
        +--rw tunnel-termination-point* [tunnel-tp-id]
           +--rw tunnel-tp-id                           binary
           +--rw admin-status?
           |       te-types:te-admin-status
           +--rw name?                                  string
           +--rw switching-capability?                  identityref
           +--rw encoding?                              identityref
           +--rw inter-layer-lock-id*                   uint32
           +--rw protection-type?                       identityref
           +--rw client-layer-adaptation
           |  +--rw switching-capability*
           |          [switching-capability encoding]
           |     +--rw switching-capability    identityref
           |     +--rw encoding                identityref
           |     +--rw te-bandwidth
           |        +--rw (technology)?
           |           +--:(generic)
           |              +--rw generic?   te-bandwidth
           +--rw local-link-connectivities
           |  +--rw number-of-entries?         uint16
           |  +--rw label-restrictions
           |  |  +--rw label-restriction* [index]
           |  |     +--rw restriction?    enumeration
           |  |     +--rw index           uint32
           |  |     +--rw label-start
           |  |     |  +--rw te-label
           |  |     |     +--rw (technology)?
           |  |     |     |  +--:(generic)
           |  |     |     |     +--rw generic?
           |  |     |     |             rt-types:generalized-label
           |  |     |     +--rw direction?       te-label-direction
           |  |     +--rw label-end
           |  |     |  +--rw te-label
           |  |     |     +--rw (technology)?
           |  |     |     |  +--:(generic)
           |  |     |     |     +--rw generic?
           |  |     |     |             rt-types:generalized-label
           |  |     |     +--rw direction?       te-label-direction
           |  |     +--rw label-step
           |  |     |  +--rw (technology)?
           |  |     |     +--:(generic)
           |  |     |        +--rw generic?   int32
           |  |     +--rw range-bitmap?   yang:hex-string
           |  +--rw is-allowed?                boolean
           |  +--rw underlay {te-topology-hierarchy}?
           |  |  +--rw enabled?                     boolean
           |  |  +--rw primary-path
           |  |  |  +--rw network-ref?
           |  |  |  |       -> /nw:networks/network/network-id
           |  |  |  +--rw path-element* [path-element-id]
           |  |  |     +--rw path-element-id              uint32
           |  |  |     +--rw (type)?
           |  |  |        +--:(numbered-node-hop)
           |  |  |        |  +--rw numbered-node-hop
           |  |  |        |     +--rw node-id     te-node-id
           |  |  |        |     +--rw hop-type?   te-hop-type
           |  |  |        +--:(numbered-link-hop)
           |  |  |        |  +--rw numbered-link-hop
           |  |  |        |     +--rw link-tp-id    te-tp-id
           |  |  |        |     +--rw hop-type?     te-hop-type
           |  |  |        |     +--rw direction?    te-link-direction
           |  |  |        +--:(unnumbered-link-hop)
           |  |  |        |  +--rw unnumbered-link-hop
           |  |  |        |     +--rw link-tp-id    te-tp-id
           |  |  |        |     +--rw node-id       te-node-id
           |  |  |        |     +--rw hop-type?     te-hop-type
           |  |  |        |     +--rw direction?    te-link-direction
           |  |  |        +--:(as-number)
           |  |  |        |  +--rw as-number-hop
           |  |  |        |     +--rw as-number    inet:as-number
           |  |  |        |     +--rw hop-type?    te-hop-type
           |  |  |        +--:(label)
           |  |  |           +--rw label-hop
           |  |  |              +--rw te-label
           |  |  |                 +--rw (technology)?
           |  |  |                 |  +--:(generic)
           |  |  |                 |     +--rw generic?
           |  |  |                 |             rt-types:generalized-
 label
           |  |  |                 +--rw direction?
           |  |  |                         te-label-direction
           |  |  +--rw backup-path* [index]
           |  |  |  +--rw index           uint32
           |  |  |  +--rw network-ref?
           |  |  |  |       -> /nw:networks/network/network-id
           |  |  |  +--rw path-element* [path-element-id]
           |  |  |     +--rw path-element-id              uint32
           |  |  |     +--rw (type)?
           |  |  |        +--:(numbered-node-hop)
           |  |  |        |  +--rw numbered-node-hop
           |  |  |        |     +--rw node-id     te-node-id
           |  |  |        |     +--rw hop-type?   te-hop-type
           |  |  |        +--:(numbered-link-hop)
           |  |  |        |  +--rw numbered-link-hop
           |  |  |        |     +--rw link-tp-id    te-tp-id
           |  |  |        |     +--rw hop-type?     te-hop-type
           |  |  |        |     +--rw direction?    te-link-direction
           |  |  |        +--:(unnumbered-link-hop)
           |  |  |        |  +--rw unnumbered-link-hop
           |  |  |        |     +--rw link-tp-id    te-tp-id
           |  |  |        |     +--rw node-id       te-node-id
           |  |  |        |     +--rw hop-type?     te-hop-type
           |  |  |        |     +--rw direction?    te-link-direction
           |  |  |        +--:(as-number)
           |  |  |        |  +--rw as-number-hop
           |  |  |        |     +--rw as-number    inet:as-number
           |  |  |        |     +--rw hop-type?    te-hop-type
           |  |  |        +--:(label)
           |  |  |           +--rw label-hop
           |  |  |              +--rw te-label
           |  |  |                 +--rw (technology)?
           |  |  |                 |  +--:(generic)
           |  |  |                 |     +--rw generic?
           |  |  |                 |             rt-types:generalized-
 label
           |  |  |                 +--rw direction?
           |  |  |                         te-label-direction
           |  |  +--rw protection-type?             identityref
           |  |  +--rw tunnel-termination-points
           |  |  |  +--rw source?        binary
           |  |  |  +--rw destination?   binary
           |  |  +--rw tunnels
           |  |     +--rw sharing?   boolean
           |  |     +--rw tunnel* [tunnel-name]
           |  |        +--rw tunnel-name    string
           |  |        +--rw sharing?       boolean
           |  +--rw path-constraints
           |  |  +--rw te-bandwidth
           |  |  |  +--rw (technology)?
           |  |  |     +--:(generic)
           |  |  |        +--rw generic?   te-bandwidth
           |  |  +--rw link-protection?          identityref
           |  |  +--rw setup-priority?           uint8
           |  |  +--rw hold-priority?            uint8
           |  |  +--rw signaling-type?           identityref
           |  |  +--rw path-metric-bounds
           |  |  |  +--rw path-metric-bound* [metric-type]
           |  |  |     +--rw metric-type    identityref
           |  |  |     +--rw upper-bound?   uint64
           |  |  +--rw path-affinities-values
           |  |  |  +--rw path-affinities-value* [usage]
           |  |  |     +--rw usage    identityref
           |  |  |     +--rw value?   admin-groups
           |  |  +--rw path-affinity-names
           |  |  |  +--rw path-affinity-name* [usage]
           |  |  |     +--rw usage            identityref
           |  |  |     +--rw affinity-name* [name]
           |  |  |        +--rw name    string
           |  |  +--rw path-srlgs-lists
           |  |  |  +--rw path-srlgs-list* [usage]
           |  |  |     +--rw usage     identityref
           |  |  |     +--rw values*   srlg
           |  |  +--rw path-srlgs-names
           |  |  |  +--rw path-srlgs-name* [usage]
           |  |  |     +--rw usage    identityref
           |  |  |     +--rw names*   string
           |  |  +--rw disjointness?             te-path-disjointness
           |  +--rw optimizations
           |  |  +--rw (algorithm)?
           |  |     +--:(metric) {path-optimization-metric}?
           |  |     |  +--rw optimization-metric* [metric-type]
           |  |     |  |  +--rw metric-type
           |  |     |  |  |       identityref
           |  |     |  |  +--rw weight?
           |  |     |  |  |       uint8
           |  |     |  |  +--rw explicit-route-exclude-objects
           |  |     |  |  |  +--rw route-object-exclude-object*
           |  |     |  |  |          [index]
           |  |     |  |  |     +--rw index
           |  |     |  |  |     |       uint32
           |  |     |  |  |     +--rw (type)?
           |  |     |  |  |        +--:(numbered-node-hop)
           |  |     |  |  |        |  +--rw numbered-node-hop
           |  |     |  |  |        |     +--rw node-id     te-node-id
           |  |     |  |  |        |     +--rw hop-type?   te-hop-type
           |  |     |  |  |        +--:(numbered-link-hop)
           |  |     |  |  |        |  +--rw numbered-link-hop
           |  |     |  |  |        |     +--rw link-tp-id    te-tp-id
           |  |     |  |  |        |     +--rw hop-type?
           |  |     |  |  |        |     |       te-hop-type
           |  |     |  |  |        |     +--rw direction?
           |  |     |  |  |        |             te-link-direction
           |  |     |  |  |        +--:(unnumbered-link-hop)
           |  |     |  |  |        |  +--rw unnumbered-link-hop
           |  |     |  |  |        |     +--rw link-tp-id    te-tp-id
           |  |     |  |  |        |     +--rw node-id
           |  |     |  |  |        |     |       te-node-id
           |  |     |  |  |        |     +--rw hop-type?
           |  |     |  |  |        |     |       te-hop-type
           |  |     |  |  |        |     +--rw direction?
           |  |     |  |  |        |             te-link-direction
           |  |     |  |  |        +--:(as-number)
           |  |     |  |  |        |  +--rw as-number-hop
           |  |     |  |  |        |     +--rw as-number
           |  |     |  |  |        |     |       inet:as-number
           |  |     |  |  |        |     +--rw hop-type?
           |  |     |  |  |        |             te-hop-type
           |  |     |  |  |        +--:(label)
           |  |     |  |  |        |  +--rw label-hop
           |  |     |  |  |        |     +--rw te-label
           |  |     |  |  |        |        +--rw (technology)?
           |  |     |  |  |        |        |  +--:(generic)
           |  |     |  |  |        |        |     +--rw generic?
           |  |     |  |  |        |        |             rt-
 types:generalized-label
           |  |     |  |  |        |        +--rw direction?
           |  |     |  |  |        |                te-label-direction
           |  |     |  |  |        +--:(srlg)
           |  |     |  |  |           +--rw srlg
           |  |     |  |  |              +--rw srlg?   uint32
           |  |     |  |  +--rw explicit-route-include-objects
           |  |     |  |     +--rw route-object-include-object*
           |  |     |  |             [index]
           |  |     |  |        +--rw index
           |  |     |  |        |       uint32
           |  |     |  |        +--rw (type)?
           |  |     |  |           +--:(numbered-node-hop)
           |  |     |  |           |  +--rw numbered-node-hop
           |  |     |  |           |     +--rw node-id     te-node-id
           |  |     |  |           |     +--rw hop-type?   te-hop-type
           |  |     |  |           +--:(numbered-link-hop)
           |  |     |  |           |  +--rw numbered-link-hop
           |  |     |  |           |     +--rw link-tp-id    te-tp-id
           |  |     |  |           |     +--rw hop-type?
           |  |     |  |           |     |       te-hop-type
           |  |     |  |           |     +--rw direction?
           |  |     |  |           |             te-link-direction
           |  |     |  |           +--:(unnumbered-link-hop)
           |  |     |  |           |  +--rw unnumbered-link-hop
           |  |     |  |           |     +--rw link-tp-id    te-tp-id
           |  |     |  |           |     +--rw node-id
           |  |     |  |           |     |       te-node-id
           |  |     |  |           |     +--rw hop-type?
           |  |     |  |           |     |       te-hop-type
           |  |     |  |           |     +--rw direction?
           |  |     |  |           |             te-link-direction
           |  |     |  |           +--:(as-number)
           |  |     |  |           |  +--rw as-number-hop
           |  |     |  |           |     +--rw as-number
           |  |     |  |           |     |       inet:as-number
           |  |     |  |           |     +--rw hop-type?
           |  |     |  |           |             te-hop-type
           |  |     |  |           +--:(label)
           |  |     |  |              +--rw label-hop
           |  |     |  |                 +--rw te-label
           |  |     |  |                    +--rw (technology)?
           |  |     |  |                    |  +--:(generic)
           |  |     |  |                    |     +--rw generic?
           |  |     |  |                    |             rt-
 types:generalized-label
           |  |     |  |                    +--rw direction?
           |  |     |  |                            te-label-direction
           |  |     |  +--rw tiebreakers
           |  |     |     +--rw tiebreaker* [tiebreaker-type]
           |  |     |        +--rw tiebreaker-type    identityref
           |  |     +--:(objective-function)
           |  |              {path-optimization-objective-function}?
           |  |        +--rw objective-function
           |  |           +--rw objective-function-type?   identityref
           |  +--ro path-properties
           |  |  +--ro path-metric* [metric-type]
           |  |  |  +--ro metric-type           identityref
           |  |  |  +--ro accumulative-value?   uint64
           |  |  +--ro path-affinities-values
           |  |  |  +--ro path-affinities-value* [usage]
           |  |  |     +--ro usage    identityref
           |  |  |     +--ro value?   admin-groups
           |  |  +--ro path-affinity-names
           |  |  |  +--ro path-affinity-name* [usage]
           |  |  |     +--ro usage            identityref
           |  |  |     +--ro affinity-name* [name]
           |  |  |        +--ro name    string
           |  |  +--ro path-srlgs-lists
           |  |  |  +--ro path-srlgs-list* [usage]
           |  |  |     +--ro usage     identityref
           |  |  |     +--ro values*   srlg
           |  |  +--ro path-srlgs-names
           |  |  |  +--ro path-srlgs-name* [usage]
           |  |  |     +--ro usage    identityref
           |  |  |     +--ro names*   string
           |  |  +--ro path-route-objects
           |  |     +--ro path-route-object* [index]
           |  |        +--ro index                        uint32
           |  |        +--ro (type)?
           |  |           +--:(numbered-node-hop)
           |  |           |  +--ro numbered-node-hop
           |  |           |     +--ro node-id     te-node-id
           |  |           |     +--ro hop-type?   te-hop-type
           |  |           +--:(numbered-link-hop)
           |  |           |  +--ro numbered-link-hop
           |  |           |     +--ro link-tp-id    te-tp-id
           |  |           |     +--ro hop-type?     te-hop-type
           |  |           |     +--ro direction?    te-link-direction
           |  |           +--:(unnumbered-link-hop)
           |  |           |  +--ro unnumbered-link-hop
           |  |           |     +--ro link-tp-id    te-tp-id
           |  |           |     +--ro node-id       te-node-id
           |  |           |     +--ro hop-type?     te-hop-type
           |  |           |     +--ro direction?    te-link-direction
           |  |           +--:(as-number)
           |  |           |  +--ro as-number-hop
           |  |           |     +--ro as-number    inet:as-number
           |  |           |     +--ro hop-type?    te-hop-type
           |  |           +--:(label)
           |  |              +--ro label-hop
           |  |                 +--ro te-label
           |  |                    +--ro (technology)?
           |  |                    |  +--:(generic)
           |  |                    |     +--ro generic?
           |  |                    |             rt-types:generalized-
 label
           |  |                    +--ro direction?
           |  |                            te-label-direction
           |  +--rw local-link-connectivity* [link-tp-ref]
           |     +--rw link-tp-ref
           |     |       -> ../../../../../nt:termination-point/tp-id
           |     +--rw label-restrictions
           |     |  +--rw label-restriction* [index]
           |     |     +--rw restriction?    enumeration
           |     |     +--rw index           uint32
           |     |     +--rw label-start
           |     |     |  +--rw te-label
           |     |     |     +--rw (technology)?
           |     |     |     |  +--:(generic)
           |     |     |     |     +--rw generic?
           |     |     |     |             rt-types:generalized-label
           |     |     |     +--rw direction?       te-label-direction
           |     |     +--rw label-end
           |     |     |  +--rw te-label
           |     |     |     +--rw (technology)?
           |     |     |     |  +--:(generic)
           |     |     |     |     +--rw generic?
           |     |     |     |             rt-types:generalized-label
           |     |     |     +--rw direction?       te-label-direction
           |     |     +--rw label-step
           |     |     |  +--rw (technology)?
           |     |     |     +--:(generic)
           |     |     |        +--rw generic?   int32
           |     |     +--rw range-bitmap?   yang:hex-string
           |     +--rw is-allowed?           boolean
           |     +--rw underlay {te-topology-hierarchy}?
           |     |  +--rw enabled?                     boolean
           |     |  +--rw primary-path
           |     |  |  +--rw network-ref?
           |     |  |  |       -> /nw:networks/network/network-id
           |     |  |  +--rw path-element* [path-element-id]
           |     |  |     +--rw path-element-id              uint32
           |     |  |     +--rw (type)?
           |     |  |        +--:(numbered-node-hop)
           |     |  |        |  +--rw numbered-node-hop
           |     |  |        |     +--rw node-id     te-node-id
           |     |  |        |     +--rw hop-type?   te-hop-type
           |     |  |        +--:(numbered-link-hop)
           |     |  |        |  +--rw numbered-link-hop
           |     |  |        |     +--rw link-tp-id    te-tp-id
           |     |  |        |     +--rw hop-type?     te-hop-type
           |     |  |        |     +--rw direction?
           |     |  |        |             te-link-direction
           |     |  |        +--:(unnumbered-link-hop)
           |     |  |        |  +--rw unnumbered-link-hop
           |     |  |        |     +--rw link-tp-id    te-tp-id
           |     |  |        |     +--rw node-id       te-node-id
           |     |  |        |     +--rw hop-type?     te-hop-type
           |     |  |        |     +--rw direction?
           |     |  |        |             te-link-direction
           |     |  |        +--:(as-number)
           |     |  |        |  +--rw as-number-hop
           |     |  |        |     +--rw as-number    inet:as-number
           |     |  |        |     +--rw hop-type?    te-hop-type
           |     |  |        +--:(label)
           |     |  |           +--rw label-hop
           |     |  |              +--rw te-label
           |     |  |                 +--rw (technology)?
           |     |  |                 |  +--:(generic)
           |     |  |                 |     +--rw generic?
           |     |  |                 |             rt-
 types:generalized-label
           |     |  |                 +--rw direction?
           |     |  |                         te-label-direction
           |     |  +--rw backup-path* [index]
           |     |  |  +--rw index           uint32
           |     |  |  +--rw network-ref?
           |     |  |  |       -> /nw:networks/network/network-id
           |     |  |  +--rw path-element* [path-element-id]
           |     |  |     +--rw path-element-id              uint32
           |     |  |     +--rw (type)?
           |     |  |        +--:(numbered-node-hop)
           |     |  |        |  +--rw numbered-node-hop
           |     |  |        |     +--rw node-id     te-node-id
           |     |  |        |     +--rw hop-type?   te-hop-type
           |     |  |        +--:(numbered-link-hop)
           |     |  |        |  +--rw numbered-link-hop
           |     |  |        |     +--rw link-tp-id    te-tp-id
           |     |  |        |     +--rw hop-type?     te-hop-type
           |     |  |        |     +--rw direction?
           |     |  |        |             te-link-direction
           |     |  |        +--:(unnumbered-link-hop)
           |     |  |        |  +--rw unnumbered-link-hop
           |     |  |        |     +--rw link-tp-id    te-tp-id
           |     |  |        |     +--rw node-id       te-node-id
           |     |  |        |     +--rw hop-type?     te-hop-type
           |     |  |        |     +--rw direction?
           |     |  |        |             te-link-direction
           |     |  |        +--:(as-number)
           |     |  |        |  +--rw as-number-hop
           |     |  |        |     +--rw as-number    inet:as-number
           |     |  |        |     +--rw hop-type?    te-hop-type
           |     |  |        +--:(label)
           |     |  |           +--rw label-hop
           |     |  |              +--rw te-label
           |     |  |                 +--rw (technology)?
           |     |  |                 |  +--:(generic)
           |     |  |                 |     +--rw generic?
           |     |  |                 |             rt-
 types:generalized-label
           |     |  |                 +--rw direction?
           |     |  |                         te-label-direction
           |     |  +--rw protection-type?             identityref
           |     |  +--rw tunnel-termination-points
           |     |  |  +--rw source?        binary
           |     |  |  +--rw destination?   binary
           |     |  +--rw tunnels
           |     |     +--rw sharing?   boolean
           |     |     +--rw tunnel* [tunnel-name]
           |     |        +--rw tunnel-name    string
           |     |        +--rw sharing?       boolean
           |     +--rw path-constraints
           |     |  +--rw te-bandwidth
           |     |  |  +--rw (technology)?
           |     |  |     +--:(generic)
           |     |  |        +--rw generic?   te-bandwidth
           |     |  +--rw link-protection?          identityref
           |     |  +--rw setup-priority?           uint8
           |     |  +--rw hold-priority?            uint8
           |     |  +--rw signaling-type?           identityref
           |     |  +--rw path-metric-bounds
           |     |  |  +--rw path-metric-bound* [metric-type]
           |     |  |     +--rw metric-type    identityref
           |     |  |     +--rw upper-bound?   uint64
           |     |  +--rw path-affinities-values
           |     |  |  +--rw path-affinities-value* [usage]
           |     |  |     +--rw usage    identityref
           |     |  |     +--rw value?   admin-groups
           |     |  +--rw path-affinity-names
           |     |  |  +--rw path-affinity-name* [usage]
           |     |  |     +--rw usage            identityref
           |     |  |     +--rw affinity-name* [name]
           |     |  |        +--rw name    string
           |     |  +--rw path-srlgs-lists
           |     |  |  +--rw path-srlgs-list* [usage]
           |     |  |     +--rw usage     identityref
           |     |  |     +--rw values*   srlg
           |     |  +--rw path-srlgs-names
           |     |  |  +--rw path-srlgs-name* [usage]
           |     |  |     +--rw usage    identityref
           |     |  |     +--rw names*   string
           |     |  +--rw disjointness?
           |     |          te-path-disjointness
           |     +--rw optimizations
           |     |  +--rw (algorithm)?
           |     |     +--:(metric) {path-optimization-metric}?
           |     |     |  +--rw optimization-metric* [metric-type]
           |     |     |  |  +--rw metric-type
           |     |     |  |  |       identityref
           |     |     |  |  +--rw weight?
           |     |     |  |  |       uint8
           |     |     |  |  +--rw explicit-route-exclude-objects
           |     |     |  |  |  +--rw route-object-exclude-object*
           |     |     |  |  |          [index]
           |     |     |  |  |     +--rw index
           |     |     |  |  |     |       uint32
           |     |     |  |  |     +--rw (type)?
           |     |     |  |  |        +--:(numbered-node-hop)
           |     |     |  |  |        |  +--rw numbered-node-hop
           |     |     |  |  |        |     +--rw node-id
           |     |     |  |  |        |     |       te-node-id
           |     |     |  |  |        |     +--rw hop-type?
           |     |     |  |  |        |             te-hop-type
           |     |     |  |  |        +--:(numbered-link-hop)
           |     |     |  |  |        |  +--rw numbered-link-hop
           |     |     |  |  |        |     +--rw link-tp-id
           |     |     |  |  |        |     |       te-tp-id
           |     |     |  |  |        |     +--rw hop-type?
           |     |     |  |  |        |     |       te-hop-type
           |     |     |  |  |        |     +--rw direction?
           |     |     |  |  |        |             te-link-direction
           |     |     |  |  |        +--:(unnumbered-link-hop)
           |     |     |  |  |        |  +--rw unnumbered-link-hop
           |     |     |  |  |        |     +--rw link-tp-id
           |     |     |  |  |        |     |       te-tp-id
           |     |     |  |  |        |     +--rw node-id
           |     |     |  |  |        |     |       te-node-id
           |     |     |  |  |        |     +--rw hop-type?
           |     |     |  |  |        |     |       te-hop-type
           |     |     |  |  |        |     +--rw direction?
           |     |     |  |  |        |             te-link-direction
           |     |     |  |  |        +--:(as-number)
           |     |     |  |  |        |  +--rw as-number-hop
           |     |     |  |  |        |     +--rw as-number
           |     |     |  |  |        |     |       inet:as-number
           |     |     |  |  |        |     +--rw hop-type?
           |     |     |  |  |        |             te-hop-type
           |     |     |  |  |        +--:(label)
           |     |     |  |  |        |  +--rw label-hop
           |     |     |  |  |        |     +--rw te-label
           |     |     |  |  |        |        +--rw (technology)?
           |     |     |  |  |        |        |  +--:(generic)
           |     |     |  |  |        |        |     +--rw generic?
           |     |     |  |  |        |        |             rt-
 types:generalized-label
           |     |     |  |  |        |        +--rw direction?
           |     |     |  |  |        |                te-label-
 direction
           |     |     |  |  |        +--:(srlg)
           |     |     |  |  |           +--rw srlg
           |     |     |  |  |              +--rw srlg?   uint32
           |     |     |  |  +--rw explicit-route-include-objects
           |     |     |  |     +--rw route-object-include-object*
           |     |     |  |             [index]
           |     |     |  |        +--rw index
           |     |     |  |        |       uint32
           |     |     |  |        +--rw (type)?
           |     |     |  |           +--:(numbered-node-hop)
           |     |     |  |           |  +--rw numbered-node-hop
           |     |     |  |           |     +--rw node-id
           |     |     |  |           |     |       te-node-id
           |     |     |  |           |     +--rw hop-type?
           |     |     |  |           |             te-hop-type
           |     |     |  |           +--:(numbered-link-hop)
           |     |     |  |           |  +--rw numbered-link-hop
           |     |     |  |           |     +--rw link-tp-id
           |     |     |  |           |     |       te-tp-id
           |     |     |  |           |     +--rw hop-type?
           |     |     |  |           |     |       te-hop-type
           |     |     |  |           |     +--rw direction?
           |     |     |  |           |             te-link-direction
           |     |     |  |           +--:(unnumbered-link-hop)
           |     |     |  |           |  +--rw unnumbered-link-hop
           |     |     |  |           |     +--rw link-tp-id
           |     |     |  |           |     |       te-tp-id
           |     |     |  |           |     +--rw node-id
           |     |     |  |           |     |       te-node-id
           |     |     |  |           |     +--rw hop-type?
           |     |     |  |           |     |       te-hop-type
           |     |     |  |           |     +--rw direction?
           |     |     |  |           |             te-link-direction
           |     |     |  |           +--:(as-number)
           |     |     |  |           |  +--rw as-number-hop
           |     |     |  |           |     +--rw as-number
           |     |     |  |           |     |       inet:as-number
           |     |     |  |           |     +--rw hop-type?
           |     |     |  |           |             te-hop-type
           |     |     |  |           +--:(label)
           |     |     |  |              +--rw label-hop
           |     |     |  |                 +--rw te-label
           |     |     |  |                    +--rw (technology)?
           |     |     |  |                    |  +--:(generic)
           |     |     |  |                    |     +--rw generic?
           |     |     |  |                    |             rt-
 types:generalized-label
           |     |     |  |                    +--rw direction?
           |     |     |  |                            te-label-
 direction
           |     |     |  +--rw tiebreakers
           |     |     |     +--rw tiebreaker* [tiebreaker-type]
           |     |     |        +--rw tiebreaker-type    identityref
           |     |     +--:(objective-function)
           |     |              {path-optimization-objective-
 function}?
           |     |        +--rw objective-function
           |     |           +--rw objective-function-type?
           |     |                   identityref
           |     +--ro path-properties
           |        +--ro path-metric* [metric-type]
           |        |  +--ro metric-type           identityref
           |        |  +--ro accumulative-value?   uint64
           |        +--ro path-affinities-values
           |        |  +--ro path-affinities-value* [usage]
           |        |     +--ro usage    identityref
           |        |     +--ro value?   admin-groups
           |        +--ro path-affinity-names
           |        |  +--ro path-affinity-name* [usage]
           |        |     +--ro usage            identityref
           |        |     +--ro affinity-name* [name]
           |        |        +--ro name    string
           |        +--ro path-srlgs-lists
           |        |  +--ro path-srlgs-list* [usage]
           |        |     +--ro usage     identityref
           |        |     +--ro values*   srlg
           |        +--ro path-srlgs-names
           |        |  +--ro path-srlgs-name* [usage]
           |        |     +--ro usage    identityref
           |        |     +--ro names*   string
           |        +--ro path-route-objects
           |           +--ro path-route-object* [index]
           |              +--ro index                        uint32
           |              +--ro (type)?
           |                 +--:(numbered-node-hop)
           |                 |  +--ro numbered-node-hop
           |                 |     +--ro node-id     te-node-id
           |                 |     +--ro hop-type?   te-hop-type
           |                 +--:(numbered-link-hop)
           |                 |  +--ro numbered-link-hop
           |                 |     +--ro link-tp-id    te-tp-id
           |                 |     +--ro hop-type?     te-hop-type
           |                 |     +--ro direction?
           |                 |             te-link-direction
           |                 +--:(unnumbered-link-hop)
           |                 |  +--ro unnumbered-link-hop
           |                 |     +--ro link-tp-id    te-tp-id
           |                 |     +--ro node-id       te-node-id
           |                 |     +--ro hop-type?     te-hop-type
           |                 |     +--ro direction?
           |                 |             te-link-direction
           |                 +--:(as-number)
           |                 |  +--ro as-number-hop
           |                 |     +--ro as-number    inet:as-number
           |                 |     +--ro hop-type?    te-hop-type
           |                 +--:(label)
           |                    +--ro label-hop
           |                       +--ro te-label
           |                          +--ro (technology)?
           |                          |  +--:(generic)
           |                          |     +--ro generic?
           |                          |             rt-
 types:generalized-label
           |                          +--ro direction?
           |                                  te-label-direction
           +--ro oper-status?
           |       te-types:te-oper-status
           +--ro geolocation
           |  +--ro altitude?    int64
           |  +--ro latitude?    geographic-coordinate-degree
           |  +--ro longitude?   geographic-coordinate-degree
           +--ro statistics
           |  +--ro discontinuity-time?         yang:date-and-time
           |  +--ro tunnel-termination-point
           |  |  +--ro disables?             yang:counter32
           |  |  +--ro enables?              yang:counter32
           |  |  +--ro maintenance-clears?   yang:counter32
           |  |  +--ro maintenance-sets?     yang:counter32
           |  |  +--ro modifies?             yang:counter32
           |  |  +--ro downs?                yang:counter32
           |  |  +--ro ups?                  yang:counter32
           |  |  +--ro in-service-clears?    yang:counter32
           |  |  +--ro in-service-sets?      yang:counter32
           |  +--ro local-link-connectivity
           |     +--ro creates?    yang:counter32
           |     +--ro deletes?    yang:counter32
           |     +--ro disables?   yang:counter32
           |     +--ro enables?    yang:counter32
           |     +--ro modifies?   yang:counter32
           +--rw supporting-tunnel-termination-point*
                   [node-ref tunnel-tp-ref]
              +--rw node-ref         inet:uri
              +--rw tunnel-tp-ref    binary
   augment /nw:networks/nw:network/nt:link:
     +--rw te!
        +--rw (bundle-stack-level)?
        |  +--:(bundle)
        |  |  +--rw bundled-links
        |  |     +--rw bundled-link* [sequence]
        |  |        +--rw sequence      uint32
        |  |        +--rw src-tp-ref?   leafref
        |  |        +--rw des-tp-ref?   leafref
        |  +--:(component)
        |     +--rw component-links
        |        +--rw component-link* [sequence]
        |           +--rw sequence             uint32
        |           +--rw src-interface-ref?   string
        |           +--rw des-interface-ref?   string
        +--rw te-link-template*
        |       -> ../../../../te/templates/link-template/name
        |       {template}?
        +--rw te-link-attributes
        |  +--rw access-type?
        |  |       te-types:te-link-access-type
        |  +--rw external-domain
        |  |  +--rw network-ref?
        |  |  |       -> /nw:networks/network/network-id
        |  |  +--rw remote-te-node-id?      te-types:te-node-id
        |  |  +--rw remote-te-link-tp-id?   te-types:te-tp-id
        |  +--rw is-abstract?                      empty
        |  +--rw name?                             string
        |  +--rw underlay {te-topology-hierarchy}?
        |  |  +--rw enabled?                     boolean
        |  |  +--rw primary-path
        |  |  |  +--rw network-ref?
        |  |  |  |       -> /nw:networks/network/network-id
        |  |  |  +--rw path-element* [path-element-id]
        |  |  |     +--rw path-element-id              uint32
        |  |  |     +--rw (type)?
        |  |  |        +--:(numbered-node-hop)
        |  |  |        |  +--rw numbered-node-hop
        |  |  |        |     +--rw node-id     te-node-id
        |  |  |        |     +--rw hop-type?   te-hop-type
        |  |  |        +--:(numbered-link-hop)
        |  |  |        |  +--rw numbered-link-hop
        |  |  |        |     +--rw link-tp-id    te-tp-id
        |  |  |        |     +--rw hop-type?     te-hop-type
        |  |  |        |     +--rw direction?    te-link-direction
        |  |  |        +--:(unnumbered-link-hop)
        |  |  |        |  +--rw unnumbered-link-hop
        |  |  |        |     +--rw link-tp-id    te-tp-id
        |  |  |        |     +--rw node-id       te-node-id
        |  |  |        |     +--rw hop-type?     te-hop-type
        |  |  |        |     +--rw direction?    te-link-direction
        |  |  |        +--:(as-number)
        |  |  |        |  +--rw as-number-hop
        |  |  |        |     +--rw as-number    inet:as-number
        |  |  |        |     +--rw hop-type?    te-hop-type
        |  |  |        +--:(label)
        |  |  |           +--rw label-hop
        |  |  |              +--rw te-label
        |  |  |                 +--rw (technology)?
        |  |  |                 |  +--:(generic)
        |  |  |                 |     +--rw generic?
        |  |  |                 |             rt-types:generalized-
 label
        |  |  |                 +--rw direction?
        |  |  |                         te-label-direction
        |  |  +--rw backup-path* [index]
        |  |  |  +--rw index           uint32
        |  |  |  +--rw network-ref?
        |  |  |  |       -> /nw:networks/network/network-id
        |  |  |  +--rw path-element* [path-element-id]
        |  |  |     +--rw path-element-id              uint32
        |  |  |     +--rw (type)?
        |  |  |        +--:(numbered-node-hop)
        |  |  |        |  +--rw numbered-node-hop
        |  |  |        |     +--rw node-id     te-node-id
        |  |  |        |     +--rw hop-type?   te-hop-type
        |  |  |        +--:(numbered-link-hop)
        |  |  |        |  +--rw numbered-link-hop
        |  |  |        |     +--rw link-tp-id    te-tp-id
        |  |  |        |     +--rw hop-type?     te-hop-type
        |  |  |        |     +--rw direction?    te-link-direction
        |  |  |        +--:(unnumbered-link-hop)
        |  |  |        |  +--rw unnumbered-link-hop
        |  |  |        |     +--rw link-tp-id    te-tp-id
        |  |  |        |     +--rw node-id       te-node-id
        |  |  |        |     +--rw hop-type?     te-hop-type
        |  |  |        |     +--rw direction?    te-link-direction
        |  |  |        +--:(as-number)
        |  |  |        |  +--rw as-number-hop
        |  |  |        |     +--rw as-number    inet:as-number
        |  |  |        |     +--rw hop-type?    te-hop-type
        |  |  |        +--:(label)
        |  |  |           +--rw label-hop
        |  |  |              +--rw te-label
        |  |  |                 +--rw (technology)?
        |  |  |                 |  +--:(generic)
        |  |  |                 |     +--rw generic?
        |  |  |                 |             rt-types:generalized-
 label
        |  |  |                 +--rw direction?
        |  |  |                         te-label-direction
        |  |  +--rw protection-type?             identityref
        |  |  +--rw tunnel-termination-points
        |  |  |  +--rw source?        binary
        |  |  |  +--rw destination?   binary
        |  |  +--rw tunnels
        |  |     +--rw sharing?   boolean
        |  |     +--rw tunnel* [tunnel-name]
        |  |        +--rw tunnel-name    string
        |  |        +--rw sharing?       boolean
        |  +--rw admin-status?
        |  |       te-types:te-admin-status
        |  +--rw link-index?                       uint64
        |  +--rw administrative-group?
        |  |       te-types:admin-groups
        |  +--rw interface-switching-capability*
        |  |       [switching-capability encoding]
        |  |  +--rw switching-capability    identityref
        |  |  +--rw encoding                identityref
        |  |  +--rw max-lsp-bandwidth* [priority]
        |  |     +--rw priority        uint8
        |  |     +--rw te-bandwidth
        |  |        +--rw (technology)?
        |  |           +--:(generic)
        |  |              +--rw generic?   te-bandwidth
        |  +--rw label-restrictions
        |  |  +--rw label-restriction* [index]
        |  |     +--rw restriction?    enumeration
        |  |     +--rw index           uint32
        |  |     +--rw label-start
        |  |     |  +--rw te-label
        |  |     |     +--rw (technology)?
        |  |     |     |  +--:(generic)
        |  |     |     |     +--rw generic?
        |  |     |     |             rt-types:generalized-label
        |  |     |     +--rw direction?       te-label-direction
        |  |     +--rw label-end
        |  |     |  +--rw te-label
        |  |     |     +--rw (technology)?
        |  |     |     |  +--:(generic)
        |  |     |     |     +--rw generic?
        |  |     |     |             rt-types:generalized-label
        |  |     |     +--rw direction?       te-label-direction
        |  |     +--rw label-step
        |  |     |  +--rw (technology)?
        |  |     |     +--:(generic)
        |  |     |        +--rw generic?   int32
        |  |     +--rw range-bitmap?   yang:hex-string
        |  +--rw link-protection-type?             identityref
        |  +--rw max-link-bandwidth
        |  |  +--rw te-bandwidth
        |  |     +--rw (technology)?
        |  |        +--:(generic)
        |  |           +--rw generic?   te-bandwidth
        |  +--rw max-resv-link-bandwidth
        |  |  +--rw te-bandwidth
        |  |     +--rw (technology)?
        |  |        +--:(generic)
        |  |           +--rw generic?   te-bandwidth
        |  +--rw unreserved-bandwidth* [priority]
        |  |  +--rw priority        uint8
        |  |  +--rw te-bandwidth
        |  |     +--rw (technology)?
        |  |        +--:(generic)
        |  |           +--rw generic?   te-bandwidth
        |  +--rw te-default-metric?                uint32
        |  +--rw te-delay-metric?                  uint32
        |  +--rw te-igp-metric?                    uint32
        |  +--rw te-srlgs
        |  |  +--rw value*   te-types:srlg
        |  +--rw te-nsrlgs {nsrlg}?
        |     +--rw id*   uint32
        +--ro oper-status?                   te-types:te-oper-status
        +--ro is-transitional?               empty
        +--ro information-source?            te-info-source
        +--ro information-source-instance?   string
        +--ro information-source-state
        |  +--ro credibility-preference?    uint16
        |  +--ro logical-network-element?   string
        |  +--ro network-instance?          string
        |  +--ro topology
        |     +--ro link-ref?      leafref
        |     +--ro network-ref?   -> /nw:networks/network/network-id
        +--ro information-source-entry*
        |       [information-source information-source-instance]
        |  +--ro information-source                te-info-source
        |  +--ro information-source-instance       string
        |  +--ro information-source-state
        |  |  +--ro credibility-preference?    uint16
        |  |  +--ro logical-network-element?   string
        |  |  +--ro network-instance?          string
        |  |  +--ro topology
        |  |     +--ro link-ref?      leafref
        |  |     +--ro network-ref?
        |  |             -> /nw:networks/network/network-id
        |  +--ro link-index?                       uint64
        |  +--ro administrative-group?
        |  |       te-types:admin-groups
        |  +--ro interface-switching-capability*
        |  |       [switching-capability encoding]
        |  |  +--ro switching-capability    identityref
        |  |  +--ro encoding                identityref
        |  |  +--ro max-lsp-bandwidth* [priority]
        |  |     +--ro priority        uint8
        |  |     +--ro te-bandwidth
        |  |        +--ro (technology)?
        |  |           +--:(generic)
        |  |              +--ro generic?   te-bandwidth
        |  +--ro label-restrictions
        |  |  +--ro label-restriction* [index]
        |  |     +--ro restriction?    enumeration
        |  |     +--ro index           uint32
        |  |     +--ro label-start
        |  |     |  +--ro te-label
        |  |     |     +--ro (technology)?
        |  |     |     |  +--:(generic)
        |  |     |     |     +--ro generic?
        |  |     |     |             rt-types:generalized-label
        |  |     |     +--ro direction?       te-label-direction
        |  |     +--ro label-end
        |  |     |  +--ro te-label
        |  |     |     +--ro (technology)?
        |  |     |     |  +--:(generic)
        |  |     |     |     +--ro generic?
        |  |     |     |             rt-types:generalized-label
        |  |     |     +--ro direction?       te-label-direction
        |  |     +--ro label-step
        |  |     |  +--ro (technology)?
        |  |     |     +--:(generic)
        |  |     |        +--ro generic?   int32
        |  |     +--ro range-bitmap?   yang:hex-string
        |  +--ro link-protection-type?             identityref
        |  +--ro max-link-bandwidth
        |  |  +--ro te-bandwidth
        |  |     +--ro (technology)?
        |  |        +--:(generic)
        |  |           +--ro generic?   te-bandwidth
        |  +--ro max-resv-link-bandwidth
        |  |  +--ro te-bandwidth
        |  |     +--ro (technology)?
        |  |        +--:(generic)
        |  |           +--ro generic?   te-bandwidth
        |  +--ro unreserved-bandwidth* [priority]
        |  |  +--ro priority        uint8
        |  |  +--ro te-bandwidth
        |  |     +--ro (technology)?
        |  |        +--:(generic)
        |  |           +--ro generic?   te-bandwidth
        |  +--ro te-default-metric?                uint32
        |  +--ro te-delay-metric?                  uint32
        |  +--ro te-igp-metric?                    uint32
        |  +--ro te-srlgs
        |  |  +--ro value*   te-types:srlg
        |  +--ro te-nsrlgs {nsrlg}?
        |     +--ro id*   uint32
        +--ro recovery
        |  +--ro restoration-status?   te-types:te-recovery-status
        |  +--ro protection-status?    te-types:te-recovery-status
        +--ro underlay {te-topology-hierarchy}?
        |  +--ro dynamic?     boolean
        |  +--ro committed?   boolean
        +--ro statistics
           +--ro discontinuity-time?                yang:date-and-time
           +--ro disables?                          yang:counter32
           +--ro enables?                           yang:counter32
           +--ro maintenance-clears?                yang:counter32
           +--ro maintenance-sets?                  yang:counter32
           +--ro modifies?                          yang:counter32
           +--ro downs?                             yang:counter32
           +--ro ups?                               yang:counter32
           +--ro fault-clears?                      yang:counter32
           +--ro fault-detects?                     yang:counter32
           +--ro protection-switches?               yang:counter32
           +--ro protection-reverts?                yang:counter32
           +--ro restoration-failures?              yang:counter32
           +--ro restoration-starts?                yang:counter32
           +--ro restoration-successes?             yang:counter32
           +--ro restoration-reversion-failures?    yang:counter32
           +--ro restoration-reversion-starts?      yang:counter32
           +--ro restoration-reversion-successes?   yang:counter32
   augment /nw:networks/nw:network/nw:node/nt:termination-point:
     +--rw te-tp-id?   te-types:te-tp-id
     +--rw te!
        +--rw admin-status?
        |       te-types:te-admin-status
        +--rw name?                             string
        +--rw interface-switching-capability*
        |       [switching-capability encoding]
        |  +--rw switching-capability    identityref
        |  +--rw encoding                identityref
        |  +--rw max-lsp-bandwidth* [priority]
        |     +--rw priority        uint8
        |     +--rw te-bandwidth
        |        +--rw (technology)?
        |           +--:(generic)
        |              +--rw generic?   te-bandwidth
        +--rw inter-domain-plug-id?             binary
        +--rw inter-layer-lock-id*              uint32
        +--ro oper-status?
        |       te-types:te-oper-status
        +--ro geolocation
           +--ro altitude?    int64
           +--ro latitude?    geographic-coordinate-degree
           +--ro longitude?   geographic-coordinate-degree

Appendix B. Companion YANG Data Model for Non-NMDA-Compliant

           Implementations
 The YANG module "ietf-te-topology" defined in Section 7 is designed
 to be used in conjunction with implementations that support the
 Network Management Datastore Architecture (NMDA) defined in
 [RFC8342].  In order to allow implementations to use the model even
 in cases where NMDA is not supported, the following companion module,
 "ietf-te-topology-state", is defined as a state model that mirrors
 the module "ietf-te-topology".  However, all data nodes in this
 "ietf-te-topology-state" companion module are non-configurable; they
 are provided to represent the applied configuration or the derived
 operational states.
 This companion module is redundant and SHOULD NOT be supported by
 implementations that support NMDA; therefore, we define it below
 rather than in the main body of this document.
 As the structure of the module "ietf-te-topology-state" mirrors that
 of the module "ietf-te-topology", the YANG tree of the module
 "ietf-te-topology-state" is not depicted separately.

B.1. TE Topology State YANG Module

 This module references [RFC6001], [RFC8345], and [RFC8776].
 <CODE BEGINS> file "ietf-te-topology-state@2020-08-06.yang"
 module ietf-te-topology-state {
   yang-version 1.1;
   namespace "urn:ietf:params:xml:ns:yang:ietf-te-topology-state";
   prefix tet-s;
   import ietf-te-types {
     prefix te-types;
     reference
       "RFC 8776: Common YANG Data Types for Traffic Engineering";
   }
   import ietf-te-topology {
     prefix tet;
     reference
       "RFC 8795: YANG Data Model for Traffic Engineering (TE)
        Topologies";
   }
   import ietf-network-state {
     prefix nw-s;
     reference
       "RFC 8345: A YANG Data Model for Network Topologies";
   }
   import ietf-network-topology-state {
     prefix nt-s;
     reference
       "RFC 8345: A YANG Data Model for Network Topologies";
   }
   organization
     "IETF Traffic Engineering Architecture and Signaling (TEAS)
      Working Group";
   contact
     "WG Web:   <https://datatracker.ietf.org/wg/teas/>
      WG List:  <mailto:teas@ietf.org>
      Editor:   Xufeng Liu
                <mailto:xufeng.liu.ietf@gmail.com>
      Editor:   Igor Bryskin
                <mailto:i_bryskin@yahoo.com>
      Editor:   Vishnu Pavan Beeram
                <mailto:vbeeram@juniper.net>
      Editor:   Tarek Saad
                <mailto:tsaad@juniper.net>
      Editor:   Himanshu Shah
                <mailto:hshah@ciena.com>
      Editor:   Oscar Gonzalez de Dios
                <mailto:oscar.gonzalezdedios@telefonica.com>";
   description
     "This YANG module defines a TE topology state model.
      Copyright (c) 2020 IETF Trust and the persons identified as
      authors of the code.  All rights reserved.
      Redistribution and use in source and binary forms, with or
      without modification, is permitted pursuant to, and subject to
      the license terms contained in, the Simplified BSD License set
      forth in Section 4.c of the IETF Trust's Legal Provisions
      Relating to IETF Documents
      (https://trustee.ietf.org/license-info).
      This version of this YANG module is part of RFC 8795; see the
      RFC itself for full legal notices.";
   revision 2020-08-06 {
     description
       "Initial revision.";
     reference
       "RFC 8795: YANG Data Model for Traffic Engineering (TE)
        Topologies";
   }
   /*
    * Groupings
    */
   grouping te-node-connectivity-matrix-attributes {
     description
       "Termination point references of a connectivity matrix entry.";
     container from {
       description
         "Reference to a source Link Termination Point (LTP).";
       leaf tp-ref {
         type leafref {
           path "../../../../../../nt-s:termination-point/nt-s:tp-id";
         }
         description
           "Relative reference to a termination point.";
       }
       uses te-types:label-set-info;
     }
     container to {
       description
         "Reference to a destination LTP.";
       leaf tp-ref {
         type leafref {
           path "../../../../../../nt-s:termination-point/nt-s:tp-id";
         }
         description
           "Relative reference to a termination point.";
       }
       uses te-types:label-set-info;
     }
     uses tet:connectivity-matrix-entry-path-attributes;
   }
   // te-node-connectivity-matrix-attributes
   grouping te-node-tunnel-termination-point-llc-list {
     description
       "Local Link Connectivity List (LLCL) of a Tunnel Termination
        Point (TTP) on a TE node.";
     list local-link-connectivity {
       key "link-tp-ref";
       description
         "The termination capabilities between the TTP and the LTP.
          This capability information can be used to compute
          the tunnel path.
          The Interface Adjustment Capability Descriptors (IACDs)
          (defined in RFC 6001) on each LTP can be derived from
          this list.";
       reference
         "RFC 6001: Generalized MPLS (GMPLS) Protocol Extensions
          for Multi-Layer and Multi-Region Networks (MLN/MRN)";
       leaf link-tp-ref {
         type leafref {
           path "../../../../../nt-s:termination-point/nt-s:tp-id";
         }
         description
           "LTP.";
       }
       uses te-types:label-set-info;
       uses tet:connectivity-matrix-entry-path-attributes;
     }
     // local-link-connectivity
   }
   // te-node-tunnel-termination-point-llc-list
   /*
    * Data nodes
    */
   augment "/nw-s:networks/nw-s:network/nw-s:network-types" {
     description
       "Introduces a new network type for a TE topology.";
     container te-topology {
       presence "Indicates a TE topology";
       description
         "Its presence identifies the TE topology type.";
     }
   }
   augment "/nw-s:networks" {
     description
       "Augmentation parameters for TE topologies.";
     uses tet:te-topologies-augment;
   }
   augment "/nw-s:networks/nw-s:network" {
     when 'nw-s:network-types/tet-s:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Configuration parameters for a TE topology.";
     uses tet:te-topology-augment;
   }
   augment "/nw-s:networks/nw-s:network/nw-s:node" {
     when '../nw-s:network-types/tet-s:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Configuration parameters for TE at the node level.";
     leaf te-node-id {
       type te-types:te-node-id;
       description
         "The identifier of a node in the TE topology.
          A node is specific to a topology to which it belongs.";
     }
     container te {
       must '../te-node-id' {
         description
           "'te-node-id' is mandatory.";
       }
       must 'count(../nw-s:supporting-node)<=1' {
         description
           "For a node in a TE topology, there cannot be more
            than one supporting node.  If multiple nodes are
            abstracted, the 'underlay-topology' field is used.";
       }
       presence "TE support";
       description
         "Indicates TE support.";
       uses tet:te-node-augment;
     }
   }
   augment "/nw-s:networks/nw-s:network/nt-s:link" {
     when '../nw-s:network-types/tet-s:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Configuration parameters for TE at the link level.";
     container te {
       must 'count(../nt-s:supporting-link)<=1' {
         description
           "For a link in a TE topology, there cannot be more
            than one supporting link.  If one or more link paths are
            abstracted, the underlay is used.";
       }
       presence "TE support";
       description
         "Indicates TE support.";
       uses tet:te-link-augment;
     }
   }
   augment "/nw-s:networks/nw-s:network/nw-s:node/"
         + "nt-s:termination-point" {
     when '../../nw-s:network-types/tet-s:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Configuration parameters for TE at the termination point
        level.";
     uses tet:te-termination-point-augment;
   }
   augment "/nw-s:networks/nw-s:network/nt-s:link/te/"
         + "bundle-stack-level/bundle/bundled-links/bundled-link" {
     when '../../../../nw-s:network-types/tet-s:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Augmentation for a TE bundled link.";
     leaf src-tp-ref {
       type leafref {
         path "../../../../../nw-s:node[nw-s:node-id = "
            + "current()/../../../../nt-s:source/"
            + "nt-s:source-node]/"
            + "nt-s:termination-point/nt-s:tp-id";
         require-instance true;
       }
       description
         "Reference to another TE termination point on the
          same source node.";
     }
     leaf des-tp-ref {
       type leafref {
         path "../../../../../nw-s:node[nw-s:node-id = "
            + "current()/../../../../nt-s:destination/"
            + "nt-s:dest-node]/"
            + "nt-s:termination-point/nt-s:tp-id";
         require-instance true;
       }
       description
         "Reference to another TE termination point on the
          same destination node.";
     }
   }
   augment "/nw-s:networks/nw-s:network/nw-s:node/te/"
         + "information-source-entry/connectivity-matrices/"
         + "connectivity-matrix" {
     when '../../../../../nw-s:network-types/tet-s:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Augmentation for the TE node connectivity matrix.";
     uses te-node-connectivity-matrix-attributes;
   }
   augment "/nw-s:networks/nw-s:network/nw-s:node/te/"
         + "te-node-attributes/connectivity-matrices/"
         + "connectivity-matrix" {
     when '../../../../../nw-s:network-types/tet-s:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Augmentation for the TE node connectivity matrix.";
     uses te-node-connectivity-matrix-attributes;
   }
   augment "/nw-s:networks/nw-s:network/nw-s:node/te/"
         + "tunnel-termination-point/local-link-connectivities" {
     when '../../../../nw-s:network-types/tet-s:te-topology' {
       description
         "Augmentation parameters apply only for networks with a
          TE topology type.";
     }
     description
       "Augmentation for TE node TTP LLCs (Local Link
        Connectivities).";
     uses te-node-tunnel-termination-point-llc-list;
   }
 }
 <CODE ENDS>

Appendix C. Example: YANG Data Model for Technology-Specific

           Augmentations
 This appendix provides an example YANG module that defines a
 technology-specific TE topology model for the example-topology model
 described in Section 6.
 This module references [RFC8345].
 module example-topology {
   yang-version 1.1;
   namespace "https://example.com/example-topology";
   prefix ex-topo;
   import ietf-network {
     prefix nw;
     reference
       "RFC 8345: A YANG Data Model for Network Topologies";
   }
   import ietf-network-topology {
     prefix nt;
     reference
       "RFC 8345: A YANG Data Model for Network Topologies";
   }
   import ietf-te-topology {
     prefix tet;
     reference
       "RFC 8795: YANG Data Model for Traffic Engineering (TE)
        Topologies";
   }
   organization
     "Example Organization";
   contact
     "Editor: Example Author";
   description
     "This module defines a topology data model for the example
      technology.";
   revision 2020-06-29 {
     description
       "Initial revision.";
     reference
       "Example reference";
   }
   /*
    * Data nodes
    */
   augment "/nw:networks/nw:network/nw:network-types/"
         + "tet:te-topology" {
     description
       "Augmentation for network types to define an example topology
        type.";
     container example-topology {
       presence "Introduces a new network type for an example
                 topology";
       description
         "Its presence identifies the example topology type.";
     }
   }
   augment "/nw:networks/nw:network/tet:te" {
     when '../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     description
       "Augmentation for the network topology.";
     container attributes {
       description
         "Attributes for the example technology.";
       leaf attribute-1 {
         type uint8;
         description
           "Attribute 1 for the example technology.";
       }
     }
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes" {
     when '../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     description
       "Augmentation for node attributes.";
     container attributes {
       description
         "Attributes for the example technology.";
       leaf attribute-2 {
         type uint8;
         description
           "Attribute 2 for the example technology.";
       }
     }
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices" {
     when '../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     description
       "Augmentation for node connectivity matrices.";
     container attributes {
       description
         "Attributes for the example technology.";
       leaf attribute-3 {
         type uint8;
         description
           "Attribute 3 for the example technology.";
       }
     }
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:connectivity-matrix" {
     when '../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     description
       "Augmentation for the node connectivity matrix.";
     container attributes {
       description
         "Attributes for the example technology.";
       leaf attribute-3 {
         type uint8;
         description
           "Attribute 3 for the example technology.";
       }
     }
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point" {
     when '../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     description
       "Augmentation for a TTP.";
     container attributes {
       description
         "Attributes for the example technology.";
       leaf attribute-4 {
         type uint8;
         description
           "Attribute 4 for the example technology.";
       }
     }
   }
   augment "/nw:networks/nw:network/nw:node/nt:termination-point/"
         + "tet:te" {
     when '../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     description
       "Augmentation for an LTP.";
     container attributes {
       description
         "Attributes for the example technology.";
       leaf attribute-5 {
         type uint8;
         description
           "Attribute 5 for the example technology.";
       }
     }
   }
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:te-link-attributes" {
     when '../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     description
       "Augmentation for link attributes.";
     container attributes {
       description
         "Attributes for the example technology.";
       leaf attribute-6 {
         type uint8;
         description
           "Attribute 6 for the example technology.";
       }
     }
   }
   /*
    * Augmentations for TE bandwidth.
    */
   augment "/nw:networks/tet:te/tet:templates/"
         + "tet:link-template/tet:te-link-attributes/"
         + "tet:interface-switching-capability/tet:max-lsp-bandwidth/"
         + "tet:te-bandwidth/tet:technology" {
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/tet:te/tet:templates/"
         + "tet:link-template/tet:te-link-attributes/"
         + "tet:max-link-bandwidth/"
         + "tet:te-bandwidth/tet:technology" {
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/tet:te/tet:templates/"
         + "tet:link-template/tet:te-link-attributes/"
         + "tet:max-resv-link-bandwidth/"
         + "tet:te-bandwidth/tet:technology" {
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/tet:te/tet:templates/"
         + "tet:link-template/tet:te-link-attributes/"
         + "tet:unreserved-bandwidth/"
         + "tet:te-bandwidth/tet:technology" {
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:path-constraints/tet:te-bandwidth/tet:technology" {
     when '../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/"
         + "tet:path-constraints/tet:te-bandwidth/tet:technology" {
     when '../../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:path-constraints/tet:te-bandwidth/tet:technology" {
     when '../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/"
         + "tet:path-constraints/tet:te-bandwidth/tet:technology" {
     when '../../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:client-layer-adaptation/tet:switching-capability/"
         + "tet:te-bandwidth/tet:technology" {
     when '../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:local-link-connectivities/tet:path-constraints/"
         + "tet:te-bandwidth/tet:technology" {
     when '../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:local-link-connectivities/"
         + "tet:local-link-connectivity/tet:path-constraints/"
         + "tet:te-bandwidth/tet:technology" {
     when '../../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:te-link-attributes/"
         + "tet:interface-switching-capability/tet:max-lsp-bandwidth/"
         + "tet:te-bandwidth/tet:technology" {
     when '../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:te-link-attributes/"
         + "tet:max-link-bandwidth/"
         + "tet:te-bandwidth/tet:technology" {
     when '../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:te-link-attributes/"
         + "tet:max-resv-link-bandwidth/"
         + "tet:te-bandwidth/tet:technology" {
     when '../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:information-source-entry/"
         + "tet:interface-switching-capability/tet:max-lsp-bandwidth/"
         + "tet:te-bandwidth/tet:technology" {
     when '../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:information-source-entry/"
         + "tet:max-link-bandwidth/"
         + "tet:te-bandwidth/tet:technology" {
     when '../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:information-source-entry/"
         + "tet:max-resv-link-bandwidth/"
         + "tet:te-bandwidth/tet:technology" {
     when '../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:information-source-entry/"
         + "tet:unreserved-bandwidth/"
         + "tet:te-bandwidth/tet:technology" {
     when '../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   augment "/nw:networks/nw:network/nw:node/nt:termination-point/"
         + "tet:te/tet:interface-switching-capability/"
         + "tet:max-lsp-bandwidth/tet:te-bandwidth/tet:technology" {
     when '../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf bandwidth-1 {
           type uint32;
           description
             "Bandwidth 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for TE bandwidth.";
   }
   /*
    * Augmentations for the TE label.
    */
   augment "/nw:networks/tet:te/tet:templates/"
         + "tet:link-template/tet:te-link-attributes/"
         + "tet:underlay/tet:primary-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/tet:te/tet:templates/"
         + "tet:link-template/tet:te-link-attributes/"
         + "tet:underlay/tet:backup-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/tet:te/tet:templates/"
         + "tet:link-template/tet:te-link-attributes/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-start/tet:te-label/tet:technology" {
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/tet:te/tet:templates/"
         + "tet:link-template/tet:te-link-attributes/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-end/tet:te-label/tet:technology" {
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   /* Under te-node-attributes/connectivity-matrices */
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-start/tet:te-label/tet:technology" {
     when '../../../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-end/tet:te-label/tet:technology" {
     when '../../../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:underlay/tet:primary-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:underlay/tet:backup-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:path-properties/tet:path-route-objects/"
         + "tet:path-route-object/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   /* Under te-node-attributes/.../connectivity-matrix */
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/tet:from/tet:label-restrictions/"
         + "tet:label-restriction/tet:label-start/"
         + "tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/tet:from/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-end/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/tet:to/tet:label-restrictions/"
         + "tet:label-restriction/tet:label-start/"
         + "tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/tet:to/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-end/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/"
         + "tet:underlay/tet:primary-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/"
         + "tet:underlay/tet:backup-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:te-node-attributes/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/"
         + "tet:path-properties/tet:path-route-objects/"
         + "tet:path-route-object/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   /* Under information-source-entry/connectivity-matrices */
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-start/tet:te-label/tet:technology" {
     when '../../../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-end/tet:te-label/tet:technology" {
     when '../../../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:underlay/tet:primary-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:underlay/tet:backup-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:path-properties/tet:path-route-objects/"
         + "tet:path-route-object/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   /* Under information-source-entry/.../connectivity-matrix */
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/tet:from/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-start/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/tet:from/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-end/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/tet:to/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-start/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/tet:to/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-end/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/"
         + "tet:underlay/tet:primary-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/"
         + "tet:underlay/tet:backup-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:information-source-entry/tet:connectivity-matrices/"
         + "tet:connectivity-matrix/"
         + "tet:path-properties/tet:path-route-objects/"
         + "tet:path-route-object/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   /* Under tunnel-termination-point/local-link-connectivities */
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:local-link-connectivities/tet:label-restrictions/"
         + "tet:label-restriction/tet:label-start/tet:te-label/"
         + "tet:technology" {
     when '../../../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:local-link-connectivities/tet:label-restrictions/"
         + "tet:label-restriction/tet:label-end/"
         + "tet:te-label/tet:technology" {
     when '../../../../../../../../nw:network-types/tet:te-topology/'
        + 'ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:local-link-connectivities/tet:underlay/"
         + "tet:primary-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:local-link-connectivities/tet:underlay/"
         + "tet:backup-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:local-link-connectivities/tet:path-properties/"
         + "tet:path-route-objects/tet:path-route-object/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   /* Under tunnel-termination-point/.../local-link-connectivity */
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:local-link-connectivities/"
         + "tet:local-link-connectivity/tet:label-restrictions/"
         + "tet:label-restriction/tet:label-start/"
         + "tet:te-label/tet:technology" {
     when '../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:local-link-connectivities/"
         + "tet:local-link-connectivity/tet:label-restrictions/"
         + "tet:label-restriction/tet:label-end/"
         + "tet:te-label/tet:technology" {
     when '../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:local-link-connectivities/"
         + "tet:local-link-connectivity/tet:underlay/"
         + "tet:primary-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:local-link-connectivities/"
         + "tet:local-link-connectivity/tet:underlay/"
         + "tet:backup-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nw:node/tet:te/"
         + "tet:tunnel-termination-point/"
         + "tet:local-link-connectivities/"
         + "tet:local-link-connectivity/tet:path-properties/"
         + "tet:path-route-objects/tet:path-route-object/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   /* Under te-link-attributes */
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:te-link-attributes/"
         + "tet:label-restrictions/tet:label-restriction/"
         + "tet:label-start/tet:te-label/tet:technology" {
     when '../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:te-link-attributes/tet:label-restrictions/"
         + "tet:label-restriction/tet:label-end/"
         + "tet:te-label/tet:technology" {
     when '../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:te-link-attributes/tet:underlay/"
         + "tet:primary-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:te-link-attributes/tet:underlay/"
         + "tet:backup-path/tet:path-element/tet:type/"
         + "tet:label/tet:label-hop/tet:te-label/tet:technology" {
     when '../../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   /* Under TE link information-source-entry */
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:information-source-entry/tet:label-restrictions/"
         + "tet:label-restriction/tet:label-start/"
         + "tet:te-label/tet:technology" {
     when '../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
   augment "/nw:networks/nw:network/nt:link/tet:te/"
         + "tet:information-source-entry/tet:label-restrictions/"
         + "tet:label-restriction/tet:label-end/"
         + "tet:te-label/tet:technology" {
     when '../../../../../../../nw:network-types/'
        + 'tet:te-topology/ex-topo:example-topology' {
       description
         "Augmentation parameters apply only for networks with an
          example topology type.";
     }
     case example {
       container example {
         description
           "Attributes for the example technology.";
         leaf label-1 {
           type uint32;
           description
             "Label 1 for the example technology.";
         }
       }
     }
     description
       "Augmentation for the TE label.";
   }
 }

Acknowledgments

 The authors would like to thank Lou Berger, Sue Hares, Mazen Khaddam,
 Cyril Margaria, and Zafar Ali for participating in design discussions
 and providing valuable insights.

Contributors

 Sergio Belotti
 Nokia
 Email: sergio.belotti@nokia.com
 Dieter Beller
 Nokia
 Email: Dieter.Beller@nokia.com
 Carlo Perocchio
 Ericsson
 Email: carlo.perocchio@ericsson.com
 Italo Busi
 Huawei Technologies
 Email: Italo.Busi@huawei.com

Authors' Addresses

 Xufeng Liu
 Volta Networks
 Email: xufeng.liu.ietf@gmail.com
 Igor Bryskin
 Futurewei Technologies, Inc.
 Email: i_bryskin@yahoo.com
 Vishnu Pavan Beeram
 Juniper Networks
 Email: vbeeram@juniper.net
 Tarek Saad
 Juniper Networks
 Email: tsaad@juniper.net
 Himanshu Shah
 Ciena
 Email: hshah@ciena.com
 Oscar Gonzalez de Dios
 Telefonica
 Email: oscar.gonzalezdedios@telefonica.com
/home/gen.uk/domains/wiki.gen.uk/public_html/data/pages/rfc/rfc8795.txt · Last modified: 2020/08/06 22:51 by 127.0.0.1

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