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rfc:rfc7417

Internet Engineering Task Force (IETF) G. Karagiannis Request for Comments: 7417 Huawei Technologies Category: Experimental A. Bhargava ISSN: 2070-1721 Cisco Systems, Inc.

                                                         December 2014
Extensions to Generic Aggregate RSVP for IPv4 and IPv6 Reservations
           over Pre-Congestion Notification (PCN) Domains

Abstract

 This document specifies extensions to Generic Aggregate RSVP (RFC
 4860) for support of the Pre-Congestion Notification (PCN) Controlled
 Load (CL) and Single Marking (SM) edge behaviors over a Diffserv
 cloud using PCN.

Status of This Memo

 This document is not an Internet Standards Track specification; it is
 published for examination, experimental implementation, and
 evaluation.
 This document defines an Experimental Protocol for the Internet
 community.  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).  Not
 all documents approved by the IESG are a candidate for any level of
 Internet Standard; see Section 2 of RFC 5741.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc7417.

Karagiannis & Bhargava Experimental [Page 1] RFC 7417 Aggregate RSVP over PCN December 2014

Copyright Notice

 Copyright (c) 2014 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
 (http://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.

Karagiannis & Bhargava Experimental [Page 2] RFC 7417 Aggregate RSVP over PCN December 2014

Table of Contents

 1. Introduction ....................................................4
    1.1. Objective ..................................................4
    1.2. Overview and Motivation ....................................5
    1.3. Requirements Language and Terminology ......................8
    1.4. Organization of This Document .............................12
 2. Overview of RSVP Extensions and Operations .....................12
    2.1. Overview of RSVP Aggregation Procedures in PCN-Domains ....12
    2.2. PCN-Marking, Encoding, and Transport of
         Pre-congestion Information ................................14
    2.3. Traffic Classification within the Aggregation Region ......14
    2.4. Deaggregator (PCN-Egress-Node) Determination ..............15
    2.5. Mapping E2E Reservations onto Aggregate Reservations ......15
    2.6. Size of Aggregate Reservations ............................16
    2.7. E2E Path ADSPEC Update ....................................16
    2.8. Intra-domain Routes .......................................16
    2.9. Inter-domain Routes .......................................16
    2.10. Reservations for Multicast Sessions ......................16
    2.11. Multi-level Aggregation ..................................16
    2.12. Reliability Issues .......................................17
 3. Elements of Procedures .........................................17
    3.1. Receipt of E2E Path Message by PCN-Ingress-Node
         (Aggregating Router) ......................................17
    3.2. Handling of E2E Path Message by Interior Routers ..........17
    3.3. Receipt of E2E Path Message by PCN-Egress-Node
         (Deaggregating Router) ....................................18
    3.4. Initiation of New Aggregate Path Message by
         PCN-Ingress-Node (Aggregating Router) .....................18
    3.5. Handling of Aggregate Path Message by Interior Routers ....18
    3.6. Handling of Aggregate Path Message by
         Deaggregating Router ......................................18
    3.7. Handling of E2E Resv Message by Deaggregating Router ......19
    3.8. Handling of E2E Resv Message by Interior Routers ..........19
    3.9. Initiation of New Aggregate Resv Message by
         Deaggregating Router ......................................20
    3.10. Handling of Aggregate Resv Message by Interior Routers ...20
    3.11. Handling of E2E Resv Message by Aggregating Router .......21
    3.12. Handling of Aggregate Resv Message by
          Aggregating Router .......................................21
    3.13. Removal of E2E Reservation ...............................21
    3.14. Removal of Aggregate Reservation .........................22
    3.15. Handling of Data on Reserved E2E Flow by
          Aggregating Router .......................................22
    3.16. Procedures for Multicast Sessions ........................22
    3.17. Misconfiguration of PCN-Node .............................22
    3.18. PCN-Based Flow Termination ...............................22

Karagiannis & Bhargava Experimental [Page 3] RFC 7417 Aggregate RSVP over PCN December 2014

 4. Protocol Elements ..............................................23
    4.1. PCN Objects ...............................................24
 5. Security Considerations ........................................28
 6. IANA Considerations ............................................29
 7. References .....................................................29
    7.1. Normative References ......................................29
    7.2. Informative References ....................................30
 Appendix A. Example Signaling Flow ................................33
 Acknowledgments ...................................................35
 Authors' Addresses ................................................36

1. Introduction

1.1. Objective

 Pre-Congestion Notification (PCN) can support the Quality of Service
 (QoS) of inelastic flows within a Diffserv domain in a simple,
 scalable, and robust fashion.  Two mechanisms are used: admission
 control and flow termination.  Admission control is used to decide
 whether to admit or block a new flow request, while flow termination
 is used in abnormal circumstances to decide whether to terminate some
 of the existing flows.  To support these two features, the overall
 rate of PCN-traffic is metered on every link in the domain, and
 PCN-packets are appropriately marked when certain configured rates
 are exceeded.  These configured rates are below the rate of the link,
 thus providing notification to boundary nodes about overloads before
 any congestion occurs (hence "pre-congestion" notification).  The
 PCN-egress-nodes measure the rates of differently marked PCN-traffic
 in periodic intervals and report these rates to the Decision Points
 for admission control and flow termination; the Decision Points use
 these rates to make decisions.  The Decision Points may be collocated
 with the PCN-ingress-nodes, or their function may be implemented in
 another node.  For more details, see [RFC5559], [RFC6661], and
 [RFC6662].
 The main objective of this document is to specify the signaling
 protocol that can be used within a PCN-domain to carry reports from a
 PCN-ingress-node to a PCN Decision Point, considering that the PCN
 Decision Point and PCN-egress-node are collocated.
 If the PCN Decision Point is not collocated with the PCN-egress-node,
 then additional signaling procedures are required that are out of
 scope for this document.  Moreover, as mentioned above, this
 architecture conforms with Policy-Based Admission Control (PBAC),
 where the Decision Point is located in a node other than the
 PCN-ingress-node [RFC2753].

Karagiannis & Bhargava Experimental [Page 4] RFC 7417 Aggregate RSVP over PCN December 2014

 Several signaling protocols can be used to carry information between
 PCN-boundary-nodes (PCN-ingress-node and PCN-egress-node).  However,
 since (1) both the PCN-egress-node and PCN-ingress-node are located
 on the data path and (2) the admission control procedure needs to be
 done at the PCN-egress-node, a signaling protocol that follows the
 same path as the data path, like RSVP, is more suited for this
 purpose.  In particular, this document specifies extensions to
 Generic Aggregate RSVP [RFC4860] for support of the PCN Controlled
 Load (CL) and Single Marking (SM) edge behaviors over a Diffserv
 cloud using Pre-Congestion Notification.
 This document is published as an Experimental document in order to:
 o  validate industry interest by allowing implementation and
    deployment
 o  gather operational experience, particularly related to dynamic
    interactions of RSVP signaling and PCN, and corresponding levels
    of performance
 Support for the techniques specified in this document involves RSVP
 functionality in boundary nodes of a PCN-domain whose interior nodes
 forward RSVP traffic without performing RSVP functionality.

1.2. Overview and Motivation

 Two main QoS architectures have been specified by the IETF: the
 Integrated Services (Intserv) [RFC1633] architecture and the
 Differentiated Services (Diffserv) architecture ([RFC2475]).
 Intserv provides methods for the delivery of end-to-end QoS to
 applications over heterogeneous networks.  One of the QoS signaling
 protocols used by the Intserv architecture is RSVP [RFC2205], which
 can be used by applications to request per-flow resources from the
 network.  These RSVP requests can be admitted or rejected by the
 network.  Applications can express their quantifiable resource
 requirements using Intserv parameters as defined in [RFC2211] and
 [RFC2212].  The Controlled Load (CL) service [RFC2211] is a form of
 QoS that closely approximates the QoS that the same flow would
 receive from a lightly loaded network element.  The CL service is
 useful for inelastic flows such as those used for real-time media.
 The Diffserv architecture can support the differentiated treatment of
 packets in very large-scale environments.  While Intserv and RSVP
 classify packets per flow, Diffserv networks classify packets into
 one of a small number of aggregated flows or "classes", based on the
 Diffserv Codepoint (DSCP) in the packet IP header.  At each Diffserv
 router, packets are subjected to a "Per Hop Behavior" (PHB), which is

Karagiannis & Bhargava Experimental [Page 5] RFC 7417 Aggregate RSVP over PCN December 2014

 invoked by the DSCP.  The primary benefit of Diffserv is its
 scalability, since the need for per-flow state and per-flow
 processing is eliminated.
 However, Diffserv does not include any mechanism for communication
 between applications and the network.  Several solutions have been
 specified to solve this issue.  One of these solutions is Intserv
 over Diffserv [RFC2998], including Resource-Based Admission Control
 (RBAC), PBAC, assistance in traffic identification/classification,
 and traffic conditioning.  Intserv over Diffserv can operate over a
 statically provisioned or an RSVP-aware Diffserv region.  When it is
 RSVP aware, several mechanisms may be used to support dynamic
 provisioning and topology-aware admission control, including
 aggregate RSVP reservations, per-flow RSVP, or a bandwidth broker.
 [RFC3175] specifies aggregation of RSVP end-to-end reservations over
 aggregate RSVP reservations.  In [RFC3175], the RSVP generic
 aggregate reservation is characterized by an RSVP SESSION object
 using the 3-tuple <source IP address, destination IP address,
 Diffserv Codepoint>.
 Several scenarios require the use of multiple generic aggregate
 reservations that are established for a given PHB from a given source
 IP address to a given destination IP address; see [RFC4923] and
 [RFC4860].  For example, multiple generic aggregate reservations can
 be applied in situations where multiple end-to-end (E2E) reservations
 using different preemption priorities need to be aggregated through a
 PCN-domain using the same PHB.  Using multiple aggregate reservations
 for the same PHB allows
 o  enforcement of the different preemption priorities within the
    aggregation region
 o  more efficient management of Diffserv resources
 o  sustainment of a larger number of E2E reservations with higher
    preemption priorities during periods of resource shortage
 In particular, [RFC4923] discusses in detail how end-to-end RSVP
 reservations can be established in a nested VPN environment through
 RSVP aggregation.
 [RFC4860] provides generic aggregate reservations by extending
 [RFC3175] to support multiple aggregate reservations for the same
 source IP address, destination IP address, and PHB (or set of PHBs).
 In particular, multiple such generic aggregate reservations can be
 established for a given PHB from a given source IP address to a given
 destination IP address.  This is achieved by adding the concept of a
 Virtual Destination Port and an Extended Virtual Destination Port in

Karagiannis & Bhargava Experimental [Page 6] RFC 7417 Aggregate RSVP over PCN December 2014

 the RSVP SESSION object.  In addition to this, the RSVP SESSION
 object for generic aggregate reservations uses the PHB Identification
 Code (PHB-ID) defined in [RFC3140] instead of using the Diffserv
 Codepoint (DSCP) used in [RFC3175].  The PHB-ID is used to identify
 the PHB, or set of PHBs, from which the Diffserv resources are to be
 reserved.
 The RSVP-like signaling protocol required to carry (1) requests from
 a PCN-egress-node to a PCN-ingress-node and (2) reports from a
 PCN-ingress-node to a PCN-egress-node needs to follow the PCN
 signaling requirements defined in [RFC6663].  In addition to that,
 the signaling protocol functionality supported by the PCN-ingress-
 nodes and PCN-egress-nodes needs to maintain logical aggregate
 constructs (i.e., ingress-egress-aggregate state) and be able to map
 E2E reservations to these aggregate constructs.  Moreover, no actual
 reservation state is needed to be maintained inside the PCN-domain,
 i.e., the PCN-interior-nodes are not maintaining any reservation
 state.
 This can be accomplished by two possible approaches:
 Approach (1):
 o  adapting the aggregation procedures of RFC 4860 to fit the PCN
    requirements with as little change as possible over the
    functionality provided in RFC 4860.
 o  hence, performing aggregate RSVP signaling (even if it is to be
    ignored by PCN-interior-nodes).
 o  using the aggregate RSVP signaling procedures to carry PCN
    information between the PCN-boundary-nodes (PCN-ingress-node and
    PCN-egress-node).
 Approach (2):
 o  adapting the aggregation procedures of RFC 4860 to fit the PCN
    requirements with significant changes over RFC 4860 (i.e., the
    aspect of the procedures that have to do with maintaining
    aggregate states and mapping the E2E reservations to aggregate
    constructs are kept, but the procedures that are specific to
    aggregate RSVP signaling and aggregate reservation
    establishment/maintenance are dropped).
 o  hence not performing aggregate RSVP signaling.
 o  piggybacking the PCN information inside the E2E RSVP signaling.

Karagiannis & Bhargava Experimental [Page 7] RFC 7417 Aggregate RSVP over PCN December 2014

 Both approaches are probably viable; however, since the operations of
 RFC 4860 have been thoroughly studied and implemented, it can be
 considered that the solution from RFC 4860 can better deal with the
 more challenging situations (rerouting in the PCN-domain, failure of
 a PCN-ingress-node, failure of a PCN-egress-node, rerouting towards a
 different edge, etc.).  This is the reason for choosing Approach (1)
 for the specification of the signaling protocol used to carry PCN
 information between the PCN-boundary-nodes (PCN-ingress-node and
 PCN-egress-node).
 As noted earlier, this document specifies extensions to Generic
 Aggregate RSVP [RFC4860] for support of the PCN Controlled Load (CL)
 and Single Marking (SM) edge behaviors over a Diffserv cloud using
 Pre-Congestion Notification.
 This document follows the PCN signaling requirements defined in
 [RFC6663] and specifies extensions to Generic Aggregate RSVP
 [RFC4860] for support of PCN edge behaviors as specified in [RFC6661]
 and [RFC6662].  Moreover, this document specifies how RSVP
 aggregation can be used to set up and maintain (1) Ingress-Egress-
 Aggregate (IEA) states at Ingress and Egress nodes and (2) generic
 aggregation of end-to-end RSVP reservations over PCN (Congestion and
 Pre-Congestion Notification) domains.
 To comply with this specification, PCN-nodes MUST be able to support
 the functionality specified in [RFC5670], [RFC5559], [RFC6660],
 [RFC6661], and [RFC6662].  Furthermore, the PCN-boundary-nodes MUST
 support the RSVP generic aggregate reservation procedures specified
 in [RFC4860], which are augmented with procedures specified in this
 document.

1.3. Requirements Language and Terminology

 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
 document are to be interpreted as described in [RFC2119].
 This document uses terms defined in [RFC4860], [RFC3175], [RFC5559],
 [RFC5670], [RFC6661], and [RFC6662].
 For readability, a number of definitions from [RFC3175] as well as
 definitions for terms used in [RFC5559], [RFC6661], and [RFC6662] are
 provided here, where some of them are augmented with new meanings:
 Aggregator
    The process in (or associated with) the router at the ingress edge
    of the aggregation region (with respect to the end-to-end RSVP
    reservation) and behaving in accordance with [RFC4860].  In this

Karagiannis & Bhargava Experimental [Page 8] RFC 7417 Aggregate RSVP over PCN December 2014

    document, it is also the PCN-ingress-node.  It is important to
    notice that in the context of this document the Aggregator must be
    able to determine the Deaggregator using the procedures specified
    in Section 4 of [RFC4860] and Section 1.4.2 of [RFC3175].
 Congestion Level Estimate (CLE)
    The ratio of PCN-marked to total PCN-traffic (measured in octets)
    received for a given ingress-egress-aggregate during a given
    measurement period.  The CLE is used to derive the PCN-admission-
    state and is also used by the report suppression procedure if
    report suppression is activated.
 Deaggregator
    The process in (or associated with) the router at the egress edge
    of the aggregation region (with respect to the end-to-end RSVP
    reservation) and behaving in accordance with [RFC4860].  In this
    document, it is also the PCN-egress-node and Decision Point.
 E2E
    End to end
 E2E Microflow
    A microflow where its associated packets are being forwarded on an
    E2E path.
 E2E Reservation
    An RSVP reservation such that:
    (1) corresponding RSVP Path messages are initiated upstream of the
        Aggregator and terminated downstream of the Deaggregator, and
    (2) corresponding RSVP Resv messages are initiated downstream of
        the Deaggregator and terminated upstream of the Aggregator,
        and
    (3) this RSVP reservation is aggregated over an Ingress-Egress-
        Aggregate (IEA) between the Aggregator and Deaggregator.
    An E2E RSVP reservation may be a per-flow reservation, which in
    this document is only maintained at the PCN-ingress-node and
    PCN-egress-node.  Alternatively, the E2E reservation may itself be
    an aggregate reservation of various types (e.g., Aggregate IP
    reservation, Aggregate IPsec reservation [RFC4860]).  As per
    regular RSVP operations, E2E RSVP reservations are unidirectional.

Karagiannis & Bhargava Experimental [Page 9] RFC 7417 Aggregate RSVP over PCN December 2014

 ETM-Rate
    The rate of excess-traffic-marked (ETM) PCN-traffic received at a
    PCN-egress-node for a given ingress-egress-aggregate in octets
    per second.
 Extended vDstPort (Extended Virtual Destination Port)
    An identifier used in the SESSION that remains constant over the
    life of the generic aggregate reservation.  The length of this
    identifier is 32 bits when IPv4 addresses are used and 128 bits
    when IPv6 addresses are used.
    A sender (or Aggregator) that wishes to narrow the scope of a
    SESSION to the sender-receiver pair (or Aggregator-Deaggregator
    pair) should place its IPv4 or IPv6 address here as a network
    unique identifier.  A sender (or Aggregator) that wishes to use a
    common session with other senders (or Aggregators) in order to use
    a shared reservation across senders (or Aggregators) must set this
    field to all zeros.  In this document, the Extended vDstPort
    should contain the IPv4 or IPv6 address of the Aggregator.
 Ingress-Egress-Aggregate (IEA)
    The collection of PCN-packets from all PCN-flows that travel in
    one direction between a specific pair of PCN-boundary-nodes.  In
    this document, one RSVP generic aggregate reservation is mapped to
    only one ingress-egress-aggregate, while one ingress-egress-
    aggregate is mapped to one or more RSVP generic aggregate
    reservations.  PCN-flows and their PCN-traffic that are mapped
    into a specific RSVP generic aggregate reservation can also be
    easily mapped into their corresponding ingress-egress-aggregate.
 Microflow (from [RFC2474])
    A single instance of an application-to-application flow of
    packets, which is identified by <source address, destination
    address, protocol id> and (where applicable) <source port,
    destination port>.
 PCN-Admission-State
    The state ("admit" or "block") derived by the Decision Point for a
    given ingress-egress-aggregate based on statistics about
    PCN-packet marking.  The Decision Point decides to admit or block
    new flows offered to the aggregate based on the current value of
    the PCN-admission-state.
 PCN-Boundary-Node
    A PCN-node that connects one PCN-domain to a node in either
    another PCN-domain or a non-PCN-domain.

Karagiannis & Bhargava Experimental [Page 10] RFC 7417 Aggregate RSVP over PCN December 2014

 PCN-Domain
    A PCN-capable domain; a contiguous set of PCN-enabled nodes that
    perform Diffserv scheduling [RFC2474]; the complete set of
    PCN-nodes that in principle can, through PCN-marking packets,
    influence decisions about flow admission and termination within
    the domain; includes the PCN-egress-nodes, which measure these
    PCN-marks, and the PCN-ingress-nodes.
 PCN-Egress-Node
    A PCN-boundary-node in its role in handling traffic as it leaves a
    PCN-domain.  In this document, the PCN-egress-node also operates
    as a Decision Point and Deaggregator.
 PCN-Flow
    The unit of PCN-traffic that the PCN-boundary-node admits (or
    terminates); the unit could be a single E2E microflow (as defined
    in [RFC2474]) or some identifiable collection of microflows.
 PCN-Ingress-Node
    A PCN-boundary-node in its role in handling traffic as it enters a
    PCN-domain.  In this document, the PCN-ingress-node also operates
    as an Aggregator.
 PCN-Interior-Node
    A node in a PCN-domain that is not a PCN-boundary-node.
 PCN-Node
    A PCN-boundary-node or a PCN-interior-node.
 PCN-Sent-Rate
    The rate of PCN-traffic received at a PCN-ingress-node and
    destined for a given ingress-egress-aggregate in octets per
    second.
 PCN-Traffic, PCN-Packets, PCN-BA
    A PCN-domain carries traffic of different Diffserv Behavior
    Aggregates (BAs) [RFC2474].  The PCN-BA uses the PCN mechanisms to
    carry PCN-traffic, and the corresponding packets are PCN-packets.
    The same network will carry traffic of other Diffserv BAs.  The
    PCN-BA is distinguished by a combination of the Diffserv Codepoint
    (DSCP) and Explicit Congestion Notification (ECN) fields.
 PHB-ID (Per Hop Behavior Identification Code)
    A 16-bit field containing the Per Hop Behavior Identification Code
    of the PHB, or of the set of PHBs, from which Diffserv resources
    are to be reserved.  This field must be encoded as specified in
    Section 2 of [RFC3140].

Karagiannis & Bhargava Experimental [Page 11] RFC 7417 Aggregate RSVP over PCN December 2014

 RSVP Generic Aggregate Reservation
    An RSVP reservation that is identified by using the RSVP SESSION
    object for generic RSVP aggregate reservation.  This RSVP SESSION
    object is based on the RSVP SESSION object specified in [RFC4860],
    augmented with the following information:
    o  The IPv4 DestAddress, IPv6 DestAddress should be set to the
       IPv4 or IPv6 destination addresses, respectively, of the
       Deaggregator (PCN-egress-node).
    o  The PHB-ID should be set equal to PCN-compatible Diffserv
       Codepoint(s).
    o  The Extended vDstPort should be set to the IPv4 or IPv6
       destination addresses, of the Aggregator (PCN-ingress-node).
 VDstPort (Virtual Destination Port)
    A 16-bit identifier used in the SESSION that remains constant over
    the life of the generic aggregate reservation.

1.4. Organization of This Document

 This document is organized as follows.  Section 2 gives an overview
 of RSVP extensions and operations.  The elements of the procedures
 that are used in this document are specified in Section 3.  Section 4
 describes the protocol elements.  The security considerations are
 given in Section 5, and the IANA considerations are provided in
 Section 6.

2. Overview of RSVP Extensions and Operations

2.1. Overview of RSVP Aggregation Procedures in PCN-Domains

 The PCN-boundary-nodes (see Figure 1) can support RSVP SESSIONS for
 generic aggregate reservations [RFC4860], which depend on ingress-
 egress-aggregates.  In particular, one RSVP generic aggregate
 reservation matches to only one ingress-egress-aggregate.
 However, one ingress-egress-aggregate matches to one or more RSVP
 generic aggregate reservations.  In addition, to comply with this
 specification, the PCN-boundary-nodes need to distinguish and process
 (1) RSVP SESSIONS for generic aggregate sessions and their messages
 according to [RFC4860] and (2) E2E RSVP SESSIONS and messages
 according to [RFC2205].
 This document locates all RSVP processing for a PCN-domain at
 PCN-boundary-nodes.  PCN-interior-nodes do not perform any RSVP
 functionality or maintain RSVP-related state information.  Rather,

Karagiannis & Bhargava Experimental [Page 12] RFC 7417 Aggregate RSVP over PCN December 2014

 PCN-interior-nodes forward all RSVP messages (for both generic
 aggregate reservations [RFC4860] and E2E reservations [RFC2205]) as
 if they were ordinary network traffic.
 Moreover, each Aggregator and Deaggregator (i.e., PCN-boundary-nodes)
 needs to support policies to initiate and maintain, for each pair of
 PCN-boundary-nodes of the same PCN-domain, one ingress-egress-
 aggregate.
  1. ————————-

/ PCN-domain \

       |----|      |                            |      |----|
    H--| R  |\ |-----|                       |------| /| R  |-->H
    H--|    |\\|     |   |---|     |---|     |      |//|    |-->H
       |----| \|     |   | I |     | I |     |      |/ |----|
               | Agg |======================>| Deag |
              /|     |   |   |     |   |     |      |\
    H--------//|     |   |---|     |---|     |      |\\-------->H
    H--------/ |-----|                       |------| \-------->H
                   |                            |
                    \                          /
                     --------------------------
    H     = Host requesting end-to-end RSVP reservations
    R     = RSVP router
    Agg   = Aggregator (PCN-ingress-node)
    Deag  = Deaggregator (PCN-egress-node)
    I     = Interior Router (PCN-interior-node)
    -->   = E2E RSVP reservation
    ==>   = Aggregate RSVP reservation
   Figure 1: Aggregation of E2E Reservations over Generic Aggregate
         RSVP Reservations in PCN-Domains, Based on [RFC4860]
 Both the Aggregator and Deaggregator can maintain one or more RSVP
 generic aggregate reservations, but the Deaggregator is the entity
 that initiates these RSVP generic aggregate reservations.  Note that
 one RSVP generic aggregate reservation matches to only one ingress-
 egress-aggregate, while one ingress-egress-aggregate matches to one
 or more RSVP generic aggregate reservations.  This can be
 accomplished by using for the different RSVP generic aggregate
 reservations the same combinations of ingress and egress identifiers,
 but with a different PHB-ID value (see [RFC4860]).  The procedures
 for aggregation of E2E reservations over generic aggregate RSVP
 reservations are the same as the procedures specified in Section 4 of
 [RFC4860], augmented with the ones specified in Section 2.5.

Karagiannis & Bhargava Experimental [Page 13] RFC 7417 Aggregate RSVP over PCN December 2014

 One significant difference between this document and [RFC4860] is the
 fact that in this document the admission control of E2E RSVP
 reservations over the PCN-core is performed according to the PCN
 procedures, while in [RFC4860] this is achieved via first admitting
 aggregate RSVP reservations over the aggregation region and then
 admitting the E2E reservations over the aggregate RSVP reservations.
 Therefore, in this document, the RSVP generic aggregate RSVP
 reservations are not subject to admission control in the PCN-core,
 and the E2E RSVP reservations are not subject to admission control
 over the aggregate reservations.  In turn, this means that several
 procedures described in [RFC4860] are significantly simplified in
 this document:
 o  Unlike [RFC4860], the generic aggregate RSVP reservations need not
    be admitted in the PCN-core.
 o  Unlike [RFC4860], the RSVP aggregated traffic does not need to be
    tunneled between Aggregator and Deaggregator; see Section 2.3.
 o  Unlike [RFC4860], the Deaggregator need not perform admission
    control of E2E reservations over the aggregate RSVP reservations.
 o  Unlike [RFC4860], there is no need for dynamic adjustment of the
    RSVP generic aggregate reservation size; see Section 2.6.

2.2. PCN-Marking, Encoding, and Transport of Pre-congestion Information

 The method of PCN-marking within the PCN-domain is specified in
 [RFC5670].  In addition, the method of encoding and transport of
 pre-congestion information is specified in [RFC6660].  The PHB-ID
 (Per Hop Behavior Identification Code) used SHOULD be set equal to
 PCN-compatible Diffserv Codepoint(s).

2.3. Traffic Classification within the Aggregation Region

 The PCN-ingress marks a PCN-BA using PCN-marking (i.e., a combination
 of the DSCP and ECN fields), which interior nodes use to classify
 PCN-traffic.  The PCN-traffic (e.g., E2E microflows) belonging to an
 RSVP generic aggregate reservation can be classified only at the
 PCN-boundary-nodes (i.e., Aggregator and Deaggregator) by using the
 RSVP SESSION object for RSVP generic aggregate reservations; see
 Section 2.1 of [RFC4860].  Note that the DSCP value included in the
 SESSION object SHOULD be set equal to a PCN-compatible Diffserv
 Codepoint.  Since no admission control procedures over the RSVP
 generic aggregate reservations in the PCN-core are required, unlike
 [RFC4860], the RSVP aggregated traffic need not be tunneled between
 Aggregator and Deaggregator.  In this document, one RSVP generic
 aggregate reservation is mapped to only one ingress-egress-aggregate,

Karagiannis & Bhargava Experimental [Page 14] RFC 7417 Aggregate RSVP over PCN December 2014

 while one ingress-egress-aggregate is mapped to one or more RSVP
 generic aggregate reservations.  PCN-flows and their PCN-traffic that
 are mapped into a specific RSVP generic aggregate reservation can
 also easily be classified into their corresponding ingress-egress-
 aggregate.  The method of traffic conditioning of PCN-traffic and
 non-PCN-traffic, as well as the method of PHB configuration, are
 described in [RFC6661] and [RFC6662].

2.4. Deaggregator (PCN-Egress-Node) Determination

 This document assumes the same dynamic Deaggregator determination
 method as that used in [RFC4860].

2.5. Mapping E2E Reservations onto Aggregate Reservations

 To comply with this specification, for the mapping of E2E
 reservations onto aggregate reservations, the same methods MUST be
 used as the ones described in Section 4 of [RFC4860], augmented by
 the following rules:
 o  An Aggregator (PCN-ingress-node) or Deaggregator (PCN-egress-node
    and Decision Point) MUST use one or more policies to determine
    whether an RSVP generic aggregate reservation can be mapped into
    an ingress-egress-aggregate.  This can be accomplished by using
    for the different RSVP generic aggregate reservations the same
    combinations of ingress and egress identifiers, but with a
    different PHB-ID value (see [RFC4860]) corresponding to the PCN
    specifications -- in particular, the RSVP SESSION object specified
    in [RFC4860], augmented with the following information:
    o  The IPv4 DestAddress, IPv6 DestAddress MUST be set to the IPv4
       or IPv6 destination addresses, respectively, of the
       Deaggregator (PCN-egress-node); see [RFC4860].  Note that the
       PCN-domain is considered as being only one RSVP hop (for
       generic aggregate RSVP or E2E RSVP).  This means that the next
       RSVP hop for the Aggregator in the downstream direction is the
       Deaggregator and the next RSVP hop for the Deaggregator in the
       upstream direction is the Aggregator.
    o  The PHB-ID (Per Hop Behavior Identification Code) SHOULD be set
       equal to PCN-compatible Diffserv Codepoint(s).
    o  The Extended vDstPort SHOULD be set to the IPv4 or IPv6
       destination addresses of the Aggregator (PCN-ingress-node); see
       [RFC4860].

Karagiannis & Bhargava Experimental [Page 15] RFC 7417 Aggregate RSVP over PCN December 2014

2.6. Size of Aggregate Reservations

 Since (1) no admission control of E2E reservations over the RSVP
 aggregate reservations is required and (2) no admission control of
 the RSVP aggregate reservation over the PCN-core is required, the
 size of the generic aggregate reservation is irrelevant and can be
 set to any arbitrary value by the Deaggregator.  The Deaggregator
 SHOULD set the value of a generic aggregate reservation to a null
 bandwidth.  We also observe that there is no need for dynamic
 adjustment of the RSVP aggregate reservation size.

2.7. E2E Path ADSPEC Update

 To comply with this specification, for the update of the E2E Path
 ADSPEC, the same methods can be used as the ones described in
 [RFC4860].

2.8. Intra-domain Routes

 The PCN-interior-nodes maintain neither E2E RSVP nor RSVP generic
 aggregation states and reservations.  Therefore, intra-domain route
 changes will not affect intra-domain reservations, since such
 reservations are not maintained by the PCN-interior-nodes.
 Furthermore, it is considered that by configuration the PCN-interior-
 nodes can distinguish neither RSVP generic aggregate sessions and
 their associated messages [RFC4860] nor E2E RSVP SESSIONS and their
 associated messages [RFC2205].

2.9. Inter-domain Routes

 The PCN-charter scope precludes inter-domain considerations.
 However, for solving inter-domain route changes associated with the
 operation of the RSVP messages, the same methods SHOULD be used as
 the ones described in [RFC4860] and in Section 1.4.7 of [RFC3175].

2.10. Reservations for Multicast Sessions

 PCN does not consider reservations for multicast sessions.

2.11. Multi-level Aggregation

 PCN does not consider multi-level aggregations within the PCN-domain.
 Therefore, the PCN-interior-nodes do not support multi-level
 aggregation procedures.  However, the Aggregator and Deaggregator
 SHOULD support the multi-level aggregation procedures specified in
 [RFC4860] and in Section 1.4.9 of [RFC3175].

Karagiannis & Bhargava Experimental [Page 16] RFC 7417 Aggregate RSVP over PCN December 2014

2.12. Reliability Issues

 To comply with this specification, for solving possible reliability
 issues, the same methods MUST be used as the ones described in
 Section 4 of [RFC4860].

3. Elements of Procedures

 This section describes the procedures used to implement the aggregate
 RSVP procedure over PCN.  It is considered that the procedures for
 aggregation of E2E reservations over generic aggregate RSVP
 reservations are the same as the procedures specified in Section 4 of
 [RFC4860], except where a departure from these procedures is
 explicitly described in this section.  Please refer to Appendix B of
 [RFC2205] and Section 3 of [RFC4860] for the processing rules and
 error handling for the error cases listed below:
 o  Message formatting errors, e.g., incomplete message
 o  Unknown objects

3.1. Receipt of E2E Path Message by PCN-Ingress-Node

    (Aggregating Router)
 When the E2E Path message arrives at the exterior interface of the
 Aggregator (PCN-ingress-node), then standard RSVP generic aggregation
 [RFC4860] procedures are used.

3.2. Handling of E2E Path Message by Interior Routers

 The E2E Path messages traverse zero or more PCN-interior-nodes.  The
 PCN-interior-nodes receive the E2E Path message on an interior
 interface and forward it on another interior interface.  It is
 considered that, by configuration, the PCN-interior-nodes ignore the
 E2E RSVP signaling messages [RFC2205].  Therefore, the E2E Path
 messages are simply forwarded as normal IP datagrams.

Karagiannis & Bhargava Experimental [Page 17] RFC 7417 Aggregate RSVP over PCN December 2014

3.3. Receipt of E2E Path Message by PCN-Egress-Node

    (Deaggregating Router)
 When receiving the E2E Path message, the Deaggregator (PCN-egress-
 node and Decision Point) performs the regular procedures of
 [RFC4860], augmented with the following rules:
 o  The Deaggregator MUST NOT perform the RSVP-TTL vs. IP TTL-check
    (TTL = Time To Live) and MUST NOT update the ADSPEC Break bit.
    This is because the whole PCN-domain is effectively handled by E2E
    RSVP as a virtual link on which integrated service is indeed
    supported (and admission control performed) so that the Break bit
    MUST NOT be set; see also [RSVP-PCN-CL].
 The Deaggregator forwards the E2E Path message towards the receiver.

3.4. Initiation of New Aggregate Path Message by PCN-Ingress-Node

    (Aggregating Router)
 To comply with this specification, for the initiation of the new RSVP
 generic aggregate Path message by the Aggregator (PCN-ingress-node),
 the same methods MUST be used as the ones described in [RFC4860].

3.5. Handling of Aggregate Path Message by Interior Routers

 The Aggregate Path messages traverse zero or more PCN-interior-nodes.
 The PCN-interior-nodes receive the Aggregate Path message on an
 interior interface and forward it on another interior interface.  It
 is considered that, by configuration, the PCN-interior-nodes ignore
 the Aggregate Path signaling messages.  Therefore, the Aggregate Path
 messages are simply forwarded as normal IP datagrams.

3.6. Handling of Aggregate Path Message by Deaggregating Router

 When receiving the Aggregate Path message, the Deaggregator
 (PCN-egress-node and Decision Point) performs the regular procedures
 of [RFC4860], augmented with the following rules:
 o  When the received Aggregate Path message by the Deaggregator
    contains the RSVP-AGGREGATE-IPv4-PCN-response or RSVP-AGGREGATE-
    IPv6-PCN-response PCN objects, which carry the PCN-sent-rate, then
    the procedures specified in Section 3.18 of this document MUST be
    followed.

Karagiannis & Bhargava Experimental [Page 18] RFC 7417 Aggregate RSVP over PCN December 2014

3.7. Handling of E2E Resv Message by Deaggregating Router

 When the E2E Resv message arrives at the exterior interface of the
 Deaggregator (PCN-egress-node and Decision Point), then standard RSVP
 aggregation procedures of [RFC4860] are used, augmented with the
 following rules:
 o  The E2E RSVP SESSION associated with an E2E Resv message that
    arrives at the external interface of the Deaggregator is
    mapped/matched with an RSVP generic aggregate and with a PCN
    ingress-egress-aggregate.
 o  Depending on the type of the PCN edge behavior supported by the
    Deaggregator, the PCN admission control procedures specified in
    Section 3.3.1 of [RFC6661] or [RFC6662] MUST be followed.  Since
    no admission control procedures over the RSVP aggregate
    reservations in the PCN-core are required, unlike [RFC4860], the
    Deaggregator does not perform any admission control of the E2E
    reservation over the mapped generic aggregate RSVP reservation.
    If the PCN-based admission control procedure is successful, then
    the Deaggregator MUST allow the new flow to be admitted onto the
    associated RSVP generic aggregation reservation and onto the PCN
    ingress-egress-aggregate; see [RFC6661] and [RFC6662].  If the
    PCN-based admission control procedure is not successful, then the
    E2E Resv MUST NOT be admitted onto the associated RSVP generic
    aggregate reservation and onto the PCN ingress-egress-aggregation.
    The E2E Resv message is further processed according to [RFC4860].
 How the PCN-admission-state is maintained is specified in [RFC6661]
 and [RFC6662].

3.8. Handling of E2E Resv Message by Interior Routers

 The E2E Resv messages traversing the PCN-core are IP addressed to the
 Aggregating router and are not marked with Router Alert; therefore,
 the E2E Resv messages are simply forwarded as normal IP datagrams.

Karagiannis & Bhargava Experimental [Page 19] RFC 7417 Aggregate RSVP over PCN December 2014

3.9. Initiation of New Aggregate Resv Message by Deaggregating Router

 To comply with this specification, for the initiation of the new RSVP
 generic aggregate Resv message by the Deaggregator (PCN-egress-node
 and Decision Point), the same methods MUST be used as the ones
 described in Section 4 of [RFC4860], augmented with the following
 rules:
 o  The size of the generic aggregate reservation is irrelevant (see
    Section 2.6) and can be set to any arbitrary value by the
    PCN-egress-node.  The Deaggregator SHOULD set the value of an RSVP
    generic aggregate reservation to a null bandwidth.  We also
    observe that there is no need for dynamic adjustment of the RSVP
    generic aggregate reservation size.
 o  When [RFC6661] is used and the ETM-rate measured by the
    Deaggregator contains a non-zero value for some ingress-egress-
    aggregate (see [RFC6661] and [RFC6662]), the Deaggregator MUST
    request the PCN-ingress-node to provide an estimate of the rate
    (PCN-sent-rate) at which the Aggregator (PCN-ingress-node) is
    receiving PCN-traffic that is destined for the given ingress-
    egress-aggregate.
 o  When [RFC6662] is used and the PCN-admission-state computed by the
    Deaggregator on the basis of the CLE is "block" for the given
    ingress-egress-aggregate, the Deaggregator MUST request the
    PCN-ingress-node to provide an estimate of the rate
    (PCN-sent-rate) at which the Aggregator is receiving PCN-traffic
    that is destined for the given ingress-egress-aggregate.
 o  In the above two cases and when the PCN-sent-rate needs to be
    requested from the Aggregator, the Deaggregator MUST generate and
    send to the Aggregator a (refresh) Aggregate Resv message that
    MUST carry one of the following PCN objects (see Section 4.1),
    depending on whether IPv4 or IPv6 is supported:
    o  RSVP-AGGREGATE-IPv4-PCN-request
    o  RSVP-AGGREGATE-IPv6-PCN-request

3.10. Handling of Aggregate Resv Message by Interior Routers

 The Aggregate Resv messages traversing the PCN-core are IP addressed
 to the Aggregating router and are not marked with Router Alert;
 therefore, the Aggregate Resv messages are simply forwarded as normal
 IP datagrams.

Karagiannis & Bhargava Experimental [Page 20] RFC 7417 Aggregate RSVP over PCN December 2014

3.11. Handling of E2E Resv Message by Aggregating Router

 When the E2E Resv message arrives at the interior interface of the
 Aggregator (PCN-ingress-node), then standard RSVP aggregation
 procedures of [RFC4860] are used.

3.12. Handling of Aggregate Resv Message by Aggregating Router

 When the Aggregate Resv message arrives at the interior interface of
 the Aggregator (PCN-ingress-node), then standard RSVP aggregation
 procedures of [RFC4860] are used, augmented with the following rules:
 o  The Aggregator SHOULD use the information carried by the PCN
    objects (see Section 4) and follow the steps specified in
    Section 3.4 of [RFC6661] and [RFC6662].  If the "R" flag carried
    by the RSVP-AGGREGATE-IPv4-PCN-request or RSVP-AGGREGATE-IPv6-PCN-
    request PCN objects is set to ON (see Section 4.1), then the
    Aggregator follows the steps described in Section 3.4 of [RFC6661]
    and [RFC6662] on calculating the PCN-sent-rate.  In particular,
    the Aggregator MUST provide the estimated current rate of
    PCN-traffic received at that node and destined for a given
    ingress-egress-aggregate in octets per second (the PCN-sent-rate).
    The way this rate estimate is derived is a matter of
    implementation; see [RFC6661] or [RFC6662].
 o  The Aggregator initiates an Aggregate Path message.  In
    particular, when the Aggregator receives an Aggregate Resv message
    that carries one of the following PCN objects -- RSVP-AGGREGATE-
    IPv4-PCN-request or RSVP-AGGREGATE-IPv6-PCN-request -- with the
    "R" flag set to ON (see Section 4.1), the Aggregator initiates an
    Aggregate Path message and includes the calculated PCN-sent-rate
    in the RSVP-AGGREGATE-IPv4-PCN-response or RSVP-AGGREGATE-
    IPv6-PCN-response PCN objects (see Section 4.1), which MUST be
    carried by the Aggregate Path message.  This Aggregate Path
    message is sent towards the Deaggregator (PCN-egress-node and
    Decision Point) that requested the calculation of the
    PCN-sent-rate.

3.13. Removal of E2E Reservation

 To comply with this specification, for the removal of E2E
 reservations, the same methods MUST be used as the ones described in
 Section 4 of [RFC4860] and Section 5 of [RFC4495].

Karagiannis & Bhargava Experimental [Page 21] RFC 7417 Aggregate RSVP over PCN December 2014

3.14. Removal of Aggregate Reservation

 To comply with this specification, for the removal of RSVP generic
 aggregate reservations, the same methods MUST be used as the ones
 described in Section 4 of [RFC4860] and Section 2.10 of [RFC3175].
 In particular, should an aggregate reservation go away (presumably
 due to a configuration change, route change, or policy event), the
 E2E reservations it supports are no longer active.  They MUST be
 treated accordingly.

3.15. Handling of Data on Reserved E2E Flow by Aggregating Router

 The handling of data on the reserved E2E flow by the Aggregator
 (PCN-ingress-node) uses the procedures described in [RFC4860],
 augmented with the following:
 o  Regarding PCN-marking and traffic classification, the procedures
    defined in Sections 2.2 and 2.3 of this document are used.

3.16. Procedures for Multicast Sessions

 No multicast sessions are considered in this document.

3.17. Misconfiguration of PCN-Node

 In an event where a PCN-node is misconfigured within a PCN-domain,
 the desired behavior is the same as that described in Section 3.10.

3.18. PCN-Based Flow Termination

 When the Deaggregator (PCN-egress-node and Decision Point) needs to
 terminate an amount of traffic associated with one ingress-egress-
 aggregate (see Section 3.3.2 of [RFC6661] and [RFC6662]), then
 several procedures for terminating E2E microflows can be deployed.
 The default procedure for terminating E2E microflows (i.e.,
 PCN-flows) is as follows; see, for example, [RFC6661] and [RFC6662].
 For the same ingress-egress-aggregate, select a number of E2E
 microflows to be terminated in order to decrease the total incoming
 amount of bandwidth associated with one ingress-egress-aggregate by
 the amount of traffic to be terminated.  In this situation, the same
 mechanisms for terminating an E2E microflow can be followed as the
 mechanisms specified in [RFC2205].  However, based on a local policy,
 the Deaggregator could use other ways of selecting which microflows
 should be terminated.  For example, for the same ingress-egress-
 aggregate, select a number of E2E microflows to be terminated or to
 reduce their reserved bandwidth in order to decrease the total

Karagiannis & Bhargava Experimental [Page 22] RFC 7417 Aggregate RSVP over PCN December 2014

 incoming amount of bandwidth associated with one ingress-egress-
 aggregate by the amount of traffic to be terminated.  In this
 situation, the same mechanisms for terminating an E2E microflow or
 reducing bandwidth associated with an E2E microflow can be followed
 as the mechanisms specified in Section 5 of [RFC4495].

4. Protocol Elements

 The protocol elements in this document are using the elements defined
 in Section 4 of [RFC4860] and Section 3 of [RFC3175], augmented with
 the following rules:
 o  The DSCP value included in the SESSION object SHOULD be set equal
    to a PCN-compatible Diffserv Codepoint.
 o  The Extended vDstPort SHOULD be set to the IPv4 or IPv6
    destination addresses of the Aggregator (PCN-ingress-node); see
    [RFC4860].
 o  When the Deaggregator (PCN-egress-node and Decision Point) needs
    to request the PCN-sent-rate from the PCN-ingress-node (see
    Section 3.9 of this document), the Deaggregator MUST generate and
    send a (refresh) Aggregate Resv message to the Aggregator that
    MUST carry one of the following PCN objects (see Section 4.1),
    depending on whether IPv4 or IPv6 is supported:
    o  RSVP-AGGREGATE-IPv4-PCN-request
    o  RSVP-AGGREGATE-IPv6-PCN-request
 o  When the Aggregator receives an Aggregate Resv message that
    carries one of the following PCN objects -- RSVP-AGGREGATE-
    IPv4-PCN-request or RSVP-AGGREGATE-IPv6-PCN-request, with the "R"
    flag set to ON (see Section 4.1) -- then the Aggregator MUST
    generate and send to the Deaggregator an Aggregate Path message
    that carries one of the following PCN objects (see Section 4.1),
    depending on whether IPv4 or IPv6 is supported:
    o  RSVP-AGGREGATE-IPv4-PCN-response
    o  RSVP-AGGREGATE-IPv6-PCN-response

Karagiannis & Bhargava Experimental [Page 23] RFC 7417 Aggregate RSVP over PCN December 2014

4.1. PCN Objects

 This section describes four types of PCN objects that can be carried
 by the (refresh) Aggregate Path or the (refresh) Aggregate Resv
 messages specified in [RFC4860].
 These objects are as follows:
    o  RSVP-AGGREGATE-IPv4-PCN-request
    o  RSVP-AGGREGATE-IPv6-PCN-request
    o  RSVP-AGGREGATE-IPv4-PCN-response
    o  RSVP-AGGREGATE-IPv6-PCN-response
 o  RSVP-AGGREGATE-IPv4-PCN-request: PCN request object, when IPv4
    addresses are used:
    Class = 248 (PCN)
    C-Type = 1 (RSVP-AGGREGATE-IPv4-PCN-request)
    +-------------+-------------+-------------+-------------+
    |     IPv4 PCN-ingress-node Address (4 bytes)           |
    +-------------+-------------+-------------+-------------+
    |     IPv4 PCN-egress-node Address (4 bytes)            |
    +-------------+-------------+-------------+-------------+
    |     IPv4 Decision Point Address (4 bytes)             |
    +-------------+-------------+-------------+-------------+
    |R|     Reserved                                        |
    +-------------+-------------+-------------+-------------+

Karagiannis & Bhargava Experimental [Page 24] RFC 7417 Aggregate RSVP over PCN December 2014

 o  RSVP-AGGREGATE-IPv6-PCN-request: PCN object, when IPv6 addresses
    are used:
    Class = 248 (PCN)
    C-Type = 2 (RSVP-AGGREGATE-IPv6-PCN-request)
    +-------------+-------------+-------------+-------------+
    |                                                       |
    +                                                       +
    |                                                       |
    +     IPv6 PCN-ingress-node Address (16 bytes)          +
    |                                                       |
    +                                                       +
    |                                                       |
    +-------------+-------------+-------------+-------------+
    |                                                       |
    +                                                       +
    |                                                       |
    +     IPv6 PCN-egress-node Address (16 bytes)           +
    |                                                       |
    +                                                       +
    |                                                       |
    +-------------+-------------+-------------+-------------+
    |                                                       |
    +                                                       +
    |                                                       |
    +     Decision Point Address (16 bytes)                 +
    |                                                       |
    +                                                       +
    |                                                       |
    +-------------+-------------+-------------+-------------+
    |R|     Reserved                                        |
    +-------------+-------------+-------------+-------------+

Karagiannis & Bhargava Experimental [Page 25] RFC 7417 Aggregate RSVP over PCN December 2014

 o  RSVP-AGGREGATE-IPv4-PCN-response: PCN object, IPv4 addresses
    are used:
    Class = 248 (PCN)
    C-Type = 3 (RSVP-AGGREGATE-IPv4-PCN-response)
    +-------------+-------------+-------------+-------------+
    |     IPv4 PCN-ingress-node Address (4 bytes)           |
    +-------------+-------------+-------------+-------------+
    |     IPv4 PCN-egress-node Address (4 bytes)            |
    +-------------+-------------+-------------+-------------+
    |     IPv4 Decision Point Address (4 bytes)             |
    +-------------+-------------+-------------+-------------+
    | PCN-sent-rate                                         |
    +-------------+-------------+-------------+-------------+

Karagiannis & Bhargava Experimental [Page 26] RFC 7417 Aggregate RSVP over PCN December 2014

 o  RSVP-AGGREGATE-IPv6-PCN-response: PCN object, IPv6 addresses
    are used:
    Class = 248 (PCN)
    C-Type = 4 (RSVP-AGGREGATE-IPv6-PCN-response)
    +-------------+-------------+-------------+-------------+
    |                                                       |
    +                                                       +
    |                                                       |
    +     IPv6 PCN-ingress-node Address (16 bytes)          +
    |                                                       |
    +                                                       +
    |                                                       |
    +-------------+-------------+-------------+-------------+
    |                                                       |
    +                                                       +
    |                                                       |
    +     IPv6 PCN-egress-node Address (16 bytes)           +
    |                                                       |
    +                                                       +
    |                                                       |
    +-------------+-------------+-------------+-------------+
    |                                                       |
    +                                                       +
    |                                                       |
    +     Decision Point Address (16 bytes)                 +
    |                                                       |
    +                                                       +
    |                                                       |
    +-------------+-------------+-------------+-------------+
    | PCN-sent-rate                                         |
    +-------------+-------------+-------------+-------------+
 The fields carried by the PCN object are specified in [RFC6663],
 [RFC6661], and [RFC6662]:
 o  The IPv4 or IPv6 address of the PCN-ingress-node (Aggregator) and
    the IPv4 or IPv6 address of the PCN-egress-node (Deaggregator):
    together, they specify the ingress-egress-aggregate to which the
    report refers.  According to [RFC6663], the report should carry
    the identifier of the PCN-ingress-node (Aggregator) and the
    identifier of the PCN-egress-node (Deaggregator) (typically their
    IP addresses).
 o  Decision Point Address: specifies the IPv4 or IPv6 address of the
    Decision Point.  In this document, this field MUST contain the IP
    address of the Deaggregator.

Karagiannis & Bhargava Experimental [Page 27] RFC 7417 Aggregate RSVP over PCN December 2014

 o  "R": 1-bit flag that, when set to ON, signifies, according to
    [RFC6661] and [RFC6662], that the PCN-ingress-node (Aggregator)
    MUST provide an estimate of the rate (PCN-sent-rate) at which the
    PCN-ingress-node (Aggregator) is receiving PCN-traffic that is
    destined for the given ingress-egress-aggregate.
 o  "Reserved": 31 bits that are currently not used by this document
    and are reserved.  These SHALL be set to 0 and SHALL be ignored on
    reception.
 o  PCN-sent-rate: the estimate of the rate at which the PCN-ingress-
    node (Aggregator) is receiving PCN-traffic that is destined for
    the given ingress-egress-aggregate.  It is expressed in
    octets/second; its format is a 32-bit IEEE floating-point number.
    The PCN-sent-rate is specified in [RFC6661] and [RFC6662].

5. Security Considerations

 The security considerations specified in [RFC2205], [RFC4860], and
 [RFC5559] apply to this document.  In addition, [RFC4230] and
 [RFC6411] provide useful guidance on RSVP security mechanisms.
 Security within a PCN-domain is fundamentally based on the controlled
 environment trust assumption stated in Section 6.3.1 of [RFC5559] --
 in particular, that all PCN-nodes are PCN-enabled and are trusted to
 perform accurate PCN-metering and PCN-marking.
 In the PCN-domain environments addressed by this document, Generic
 Aggregate RSVP messages specified in [RFC4860] are used for support
 of the PCN Controlled Load (CL) and Single Marking (SM) edge
 behaviors over a Diffserv cloud using Pre-Congestion Notification.
 Hence, the security mechanisms discussed in [RFC4860] are applicable.
 Specifically, the INTEGRITY object [RFC2747] [RFC3097] can be used to
 provide hop-by-hop RSVP message integrity, node authentication, and
 replay protection, thereby protecting against corruption and spoofing
 of RSVP messages and PCN feedback conveyed by RSVP messages.
 For these reasons, this document does not introduce significant
 additional security considerations beyond those discussed in
 [RFC5559] and [RFC4860].

Karagiannis & Bhargava Experimental [Page 28] RFC 7417 Aggregate RSVP over PCN December 2014

6. IANA Considerations

 IANA has modified the "Class Names, Class Numbers, and Class Types"
 subregistry of the "Resource Reservation Protocol (RSVP) Parameters"
 registry, to add a new Class Number and assign four new C-Types under
 this new Class Number, as described below; see Section 4.1:
 Class
 Number   Class Name                                  Reference
 -------  ----------------------                      -------------
 248      PCN                                         RFC 7417
 Class Types or C-Types - 248 PCN
 Value    Description                        Reference
 ------   ------------------------------     ------------
 1        RSVP-AGGREGATE-IPv4-PCN-request    RFC 7417
 2        RSVP-AGGREGATE-IPv6-PCN-request    RFC 7417
 3        RSVP-AGGREGATE-IPv4-PCN-response   RFC 7417
 4        RSVP-AGGREGATE-IPv6-PCN-response   RFC 7417

7. References

7.1. Normative References

 [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119, March 1997,
            <http://www.rfc-editor.org/info/rfc2119>.
 [RFC2205]  Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and S.
            Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1
            Functional Specification", RFC 2205, September 1997,
            <http://www.rfc-editor.org/info/rfc2205>.
 [RFC3140]  Black, D., Brim, S., Carpenter, B., and F. Le Faucheur,
            "Per Hop Behavior Identification Codes", RFC 3140,
            June 2001, <http://www.rfc-editor.org/info/rfc3140>.
 [RFC3175]  Baker, F., Iturralde, C., Le Faucheur, F., and B. Davie,
            "Aggregation of RSVP for IPv4 and IPv6 Reservations",
            RFC 3175, September 2001,
            <http://www.rfc-editor.org/info/rfc3175>.
 [RFC4495]  Polk, J. and S. Dhesikan, "A Resource Reservation Protocol
            (RSVP) Extension for the Reduction of Bandwidth of a
            Reservation Flow", RFC 4495, May 2006,
            <http://www.rfc-editor.org/info/rfc4495>.

Karagiannis & Bhargava Experimental [Page 29] RFC 7417 Aggregate RSVP over PCN December 2014

 [RFC4860]  Le Faucheur, F., Davie, B., Bose, P., Christou, C., and M.
            Davenport, "Generic Aggregate Resource ReSerVation
            Protocol (RSVP) Reservations", RFC 4860, May 2007,
            <http://www.rfc-editor.org/info/rfc4860>.
 [RFC5670]  Eardley, P., Ed., "Metering and Marking Behaviour of
            PCN-Nodes", RFC 5670, November 2009,
            <http://www.rfc-editor.org/info/rfc5670>.
 [RFC6660]  Briscoe, B., Moncaster, T., and M. Menth, "Encoding Three
            Pre-Congestion Notification (PCN) States in the IP Header
            Using a Single Diffserv Codepoint (DSCP)", RFC 6660,
            July 2012, <http://www.rfc-editor.org/info/rfc6660>.
 [RFC6661]  Charny, A., Huang, F., Karagiannis, G., Menth, M., and T.
            Taylor, Ed., "Pre-Congestion Notification (PCN) Boundary-
            Node Behavior for the Controlled Load (CL) Mode of
            Operation", RFC 6661, July 2012,
            <http://www.rfc-editor.org/info/rfc6661>.
 [RFC6662]  Charny, A., Zhang, J., Karagiannis, G., Menth, M., and T.
            Taylor, Ed., "Pre-Congestion Notification (PCN) Boundary-
            Node Behavior for the Single Marking (SM) Mode of
            Operation", RFC 6662, July 2012,
            <http://www.rfc-editor.org/info/rfc6662>.
 [RFC6663]  Karagiannis, G., Taylor, T., Chan, K., Menth, M., and P.
            Eardley, "Requirements for Signaling of Pre-Congestion
            Information in a Diffserv Domain", RFC 6663, July 2012,
            <http://www.rfc-editor.org/info/rfc6663>.

7.2. Informative References

 [RFC1633]  Braden, R., Clark, D., and S. Shenker, "Integrated
            Services in the Internet Architecture: an Overview",
            RFC 1633, June 1994,
            <http://www.rfc-editor.org/info/rfc1633>.
 [RFC2211]  Wroclawski, J., "Specification of the Controlled-Load
            Network Element Service", RFC 2211, September 1997,
            <http://www.rfc-editor.org/info/rfc2211>.
 [RFC2212]  Shenker, S., Partridge, C., and R. Guerin, "Specification
            of Guaranteed Quality of Service", RFC 2212,
            September 1997, <http://www.rfc-editor.org/info/rfc2212>.

Karagiannis & Bhargava Experimental [Page 30] RFC 7417 Aggregate RSVP over PCN December 2014

 [RFC2474]  Nichols, K., Blake, S., Baker, F., and D. Black,
            "Definition of the Differentiated Services Field (DS
            Field) in the IPv4 and IPv6 Headers", RFC 2474,
            December 1998, <http://www.rfc-editor.org/info/rfc2474>.
 [RFC2475]  Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
            and W. Weiss, "An Architecture for Differentiated
            Services", RFC 2475, December 1998,
            <http://www.rfc-editor.org/info/rfc2475>.
 [RFC2747]  Baker, F., Lindell, B., and M. Talwar, "RSVP Cryptographic
            Authentication", RFC 2747, January 2000,
            <http://www.rfc-editor.org/info/rfc2747>.
 [RFC2753]  Yavatkar, R., Pendarakis, D., and R. Guerin, "A Framework
            for Policy-based Admission Control", RFC 2753,
            January 2000, <http://www.rfc-editor.org/info/rfc2753>.
 [RFC2998]  Bernet, Y., Ford, P., Yavatkar, R., Baker, F., Zhang, L.,
            Speer, M., Braden, R., Davie, B., Wroclawski, J., and E.
            Felstaine, "A Framework for Integrated Services Operation
            over Diffserv Networks", RFC 2998, November 2000,
            <http://www.rfc-editor.org/info/rfc2998>.
 [RFC3097]  Braden, R. and L. Zhang, "RSVP Cryptographic
            Authentication -- Updated Message Type Value", RFC 3097,
            April 2001, <http://www.rfc-editor.org/info/rfc3097>.
 [RFC4230]  Tschofenig, H. and R. Graveman, "RSVP Security
            Properties", RFC 4230, December 2005,
            <http://www.rfc-editor.org/info/rfc4230>.
 [RFC4923]  Baker, F. and P. Bose, "Quality of Service (QoS) Signaling
            in a Nested Virtual Private Network", RFC 4923,
            August 2007, <http://www.rfc-editor.org/info/rfc4923>.
 [RFC5559]  Eardley, P., Ed., "Pre-Congestion Notification (PCN)
            Architecture", RFC 5559, June 2009,
            <http://www.rfc-editor.org/info/rfc5559>.

Karagiannis & Bhargava Experimental [Page 31] RFC 7417 Aggregate RSVP over PCN December 2014

 [RFC6411]  Behringer, M., Le Faucheur, F., and B. Weis,
            "Applicability of Keying Methods for RSVP Security",
            RFC 6411, October 2011,
            <http://www.rfc-editor.org/info/rfc6411>.
 [RSVP-PCN-CL]
            Le Faucheur, F., Charny, A., Briscoe, B., Eardley, P.,
            Babiarz, J., and K. Chan, "RSVP Extensions for Admission
            Control over Diffserv using Pre-congestion Notification
            (PCN)", Work in Progress, draft-lefaucheur-rsvp-ecn-01,
            June 2006.

Karagiannis & Bhargava Experimental [Page 32] RFC 7417 Aggregate RSVP over PCN December 2014

Appendix A. Example Signaling Flow

 This appendix is based on Appendix A of [RFC4860].  In particular, it
 provides an example signaling flow of the specifications detailed in
 Sections 3 and 4.
 This signaling flow assumes an environment where E2E reservations are
 aggregated over generic aggregate RSVP reservations and applied over
 a PCN-domain.  In particular, the Aggregator (PCN-ingress-node) and
 Deaggregator (PCN-egress-node) are located at the boundaries of the
 PCN-domain.  The PCN-interior-nodes are located within the
 PCN-domain, between the PCN-boundary-nodes, but are not shown in the
 diagram below.  It illustrates a possible RSVP message flow that
 could take place in the successful establishment of a unicast E2E
 reservation that is the first between a given Aggregator-Deaggregator
 pair.
      Aggregator (PCN-ingress-node)     Deaggregator (PCN-egress-node)
    E2E Path
   ----------->
                (1)
                           E2E Path
                   ------------------------------->
                                                             (2)
                    E2E PathErr(NEW-AGGREGATE-NEEDED,SOI=GApcn)
                   <----------------------------------------
 (3)
                         AggPath(Session=GApcn)
                   ------------------------------->
 (4)
                                                           E2E Path
                                                          ----------->
                                                       (5)
                         AggResv (Session=GApcn) (PCN object)
                   <-------------------------------
 (6)
                     AggResvConfirm (Session=GApcn)
                   ------------------------------>
 (7)
                                                           E2E Resv
                                                          <---------
                                                       (8)
                           E2E Resv (SOI=GApcn)
                   <-----------------------------
                (9)
      E2E Resv
   <-----------

Karagiannis & Bhargava Experimental [Page 33] RFC 7417 Aggregate RSVP over PCN December 2014

 (1) The Aggregator forwards E2E Path into the aggregation region
     after modifying its IP protocol number to RSVP-E2E-IGNORE.
 (2) Let's assume that no Aggregate Path exists.  To be able to
     accurately update the ADSPEC of the E2E Path, the Deaggregator
     needs the ADSPEC of Aggregate Path.  In this example, the
     Deaggregator elects to instruct the Aggregator to set up an
     Aggregate Path state for the PCN PHB-ID.  To do that, the
     Deaggregator sends an E2E PathErr message with a
     NEW-AGGREGATE-NEEDED PathErr code.
     The PathErr message also contains a SESSION-OF-INTEREST (SOI)
     object.  The SOI contains a GENERIC-AGGREGATE SESSION (GApcn)
     whose PHB-ID is set to the PCN PHB-ID.  The GENERIC-AGGREGATE
     SESSION contains an interface-independent Deaggregator address
     inside the DestAddress and appropriate values inside the vDstPort
     and Extended vDstPort fields.  In this document, the Extended
     vDstPort SHOULD contain the IPv4 or IPv6 address of the
     Aggregator.
 (3) The Aggregator follows the request from the Deaggregator and
     signals an Aggregate Path for the GENERIC-AGGREGATE SESSION
     (GApcn).
 (4) The Deaggregator takes into account the information contained in
     the ADSPEC from both Aggregate Paths and updates the E2E Path
     ADSPEC accordingly.  The PCN-egress-node MUST NOT perform the
     RSVP-TTL vs. IP TTL-check and MUST NOT update the ADSPEC Break
     bit.  This is because the whole PCN-domain is effectively handled
     by E2E RSVP as a virtual link on which integrated service is
     indeed supported (and admission control performed) so that the
     Break bit MUST NOT be set; see also [RSVP-PCN-CL].  The
     Deaggregator also modifies the E2E Path IP protocol number to
     RSVP before forwarding it.
 (5) In this example, the Deaggregator elects to immediately proceed
     with establishment of the generic aggregate reservation.  In
     effect, the Deaggregator can be seen as anticipating the actual
     demand of E2E reservations so that the generic aggregate
     reservation is in place when the E2E Resv request arrives, in
     order to speed up establishment of E2E reservations.  Here it is
     also assumed that the Deaggregator includes the optional
     ResvConfirm Request in the Aggregate Resv message.
 (6) The Aggregator merely complies with the received ResvConfirm
     Request and returns the corresponding Aggregate ResvConfirm.

Karagiannis & Bhargava Experimental [Page 34] RFC 7417 Aggregate RSVP over PCN December 2014

 (7) The Deaggregator has explicit confirmation that the generic
     aggregate reservation is established.
 (8) On receipt of the E2E Resv, the Deaggregator applies the mapping
     policy defined by the network administrator to map the E2E Resv
     onto a generic aggregate reservation.  Let's assume that this
     policy is such that the E2E reservation is to be mapped onto the
     generic aggregate reservation with the PCN PHB-ID=x.  After the
     previous step (7), the Deaggregator knows that a generic
     aggregate reservation (GApcn) is in place for the corresponding
     PHB-ID.  At this step, the Deaggregator maps the generic
     aggregate reservation onto one ingress-egress-aggregate
     maintained by the Deaggregator (as a PCN-egress-node); see
     Section 3.7.  The Deaggregator performs admission control of the
     E2E Resv onto the generic aggregate reservation for the PCN
     PHB-ID (GApcn).  The Deaggregator also takes into account the PCN
     admission control procedure as specified in [RFC6661] and
     [RFC6662]; see Section 3.7.  If one or both of the admission
     control procedures (the PCN-based admission control procedure
     described in Section 3.3.1 of [RFC6661] or [RFC6662], and the
     admission control procedure specified in [RFC4860]) are not
     successful, then the E2E Resv is not admitted onto the associated
     RSVP generic aggregate reservation for the PCN PHB-ID (GApcn).
     Otherwise, assuming that the generic aggregate reservation for
     the PCN (GApcn) had been established with sufficient bandwidth to
     support the E2E Resv, the Deaggregator adjusts its counter,
     tracking the unused bandwidth on the generic aggregate
     reservation.  Then it forwards the E2E Resv to the Aggregator,
     including a SESSION-OF-INTEREST object conveying the selected
     mapping onto GApcn (and hence onto the PCN PHB-ID).
 (9) The Aggregator records the mapping of the E2E Resv onto GApcn
     (and onto the PCN PHB-ID).  The Aggregator removes the SOI object
     and forwards the E2E Resv towards the sender.

Acknowledgments

 We would like to thank the authors of [RSVP-PCN-CL], since some ideas
 used in this document are based on the work initiated in
 [RSVP-PCN-CL].  Moreover, we would like to thank Bob Briscoe, David
 Black, Ken Carlberg, Tom Taylor, Philip Eardley, Michael Menth, Toby
 Moncaster, James Polk, Scott Bradner, Lixia Zhang, and Robert Sparks
 for the provided comments.  In particular, we would like to thank
 Francois Le Faucheur for contributing a significant amount of text,
 in addition to his comments.

Karagiannis & Bhargava Experimental [Page 35] RFC 7417 Aggregate RSVP over PCN December 2014

Authors' Addresses

 Georgios Karagiannis
 Huawei Technologies
 Hansaallee 205
 40549 Dusseldorf
 Germany
 EMail: Georgios.Karagiannis@huawei.com
 Anurag Bhargava
 Cisco Systems, Inc.
 7100-9 Kit Creek Road
 PO Box 14987
 Research Triangle Park, NC  27709-4987
 United States
 EMail: anuragb@cisco.com

Karagiannis & Bhargava Experimental [Page 36]

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