GENWiki

Premier IT Outsourcing and Support Services within the UK

User Tools

Site Tools


rfc:rfc7487

Internet Engineering Task Force (IETF) E. Bellagamba Request for Comments: 7487 A. Takacs Category: Standards Track G. Mirsky ISSN: 2070-1721 Ericsson

                                                          L. Andersson
                                                   Huawei Technologies
                                                         P. Skoldstrom
                                                              Acreo AB
                                                               D. Ward
                                                                 Cisco
                                                            March 2015
                          Configuration of

Proactive Operations, Administration, and Maintenance (OAM) Functions

          for MPLS-Based Transport Networks Using RSVP-TE

Abstract

 This specification describes the configuration of proactive MPLS
 Transport Profile (MPLS-TP) Operations, Administration, and
 Maintenance (OAM) functions for a given Label Switched Path (LSP)
 using a set of TLVs that are carried by the GMPLS RSVP-TE protocol
 based on the OAM Configuration Framework for GMPLS RSVP-TE.

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 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/rfc7487.

Bellagamba, et al. Standards Track [Page 1] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

Copyright Notice

 Copyright (c) 2015 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.

Bellagamba, et al. Standards Track [Page 2] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

Table of Contents

 1. Introduction ....................................................4
    1.1. Conventions Used in This Document ..........................5
         1.1.1. Terminology .........................................5
         1.1.2. Requirements Language ...............................6
 2. Overview of MPLS OAM for Transport Applications .................6
 3. Theory of Operations ............................................7
    3.1. MPLS-TP OAM Configuration Operation Overview ...............7
         3.1.1. Configuration of BFD Sessions .......................8
         3.1.2. Configuration of Performance Monitoring .............8
         3.1.3. Configuration of Fault Management Signals ...........9
    3.2. MPLS OAM Configuration Sub-TLV .............................9
         3.2.1. CV Flag Rules of Use ...............................11
    3.3. BFD Configuration Sub-TLV .................................12
         3.3.1. BFD Identifiers Sub-TLV ............................14
         3.3.2. Negotiation Timer Parameters Sub-TLV ...............15
         3.3.3. BFD Authentication Sub-TLV .........................16
         3.3.4. Traffic Class Sub-TLV ..............................17
    3.4. Performance Monitoring Sub-TLV ............................17
         3.4.1. MPLS OAM PM Loss Sub-TLV ...........................19
         3.4.2. MPLS OAM PM Delay Sub-TLV ..........................21
    3.5. MPLS OAM FMS Sub-TLV ......................................22
 4. Summary of MPLS OAM Configuration Errors .......................23
 5. IANA Considerations ............................................25
    5.1. MPLS OAM Type .............................................25
    5.2. MPLS OAM Configuration Sub-TLV ............................25
    5.3. MPLS OAM Configuration Sub-TLV Types ......................26
    5.4. BFD Configuration Sub-TLV Types ...........................26
    5.5. Performance Monitoring Sub-TLV Types ......................27
    5.6. New RSVP-TE Error Codes ...................................28
 6. Security Considerations ........................................28
 7. References .....................................................29
    7.1. Normative References ......................................29
    7.2. Informative References ....................................30
 Acknowledgements ..................................................31
 Contributors ......................................................31
 Authors' Addresses ................................................32

Bellagamba, et al. Standards Track [Page 3] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

1. Introduction

 This document describes the configuration of proactive MPLS-TP OAM
 functions for a given LSP using TLVs that use GMPLS RSVP-TE
 [RFC3473].  [RFC7260] defines use of GMPLS RSVP-TE for the
 configuration of OAM functions in a technology-agnostic way.  This
 document specifies the additional mechanisms necessary to establish
 MPLS-TP OAM entities at the maintenance points for monitoring and
 performing measurements on an LSP, as well as defining information
 elements and procedures to configure proactive MPLS-TP OAM functions
 running between Label Edge Routers (LERs).  Initialization and
 control of on-demand MPLS-TP OAM functions are expected to be carried
 out by directly accessing network nodes via a management interface;
 hence, configuration and control of on-demand OAM functions are out
 of scope for this document.
 MPLS-TP, the Transport Profile of MPLS, must, by definition
 [RFC5654], be capable of operating without a control plane.
 Therefore, there are several options for configuring MPLS-TP OAM
 without a control plane by using either a Network Management System
 (NMS), an LSP Ping, or signaling protocols such as RSVP-TE in the
 control plane.
 MPLS-TP describes a profile of MPLS that enables operational models
 typical in transport networks while providing additional OAM
 survivability and other maintenance functions not currently supported
 by MPLS.  [RFC5860] defines the requirements for the OAM
 functionality of MPLS-TP.
 Proactive MPLS-TP OAM is performed by three different protocols:
 Bidirectional Forwarding Detection (BFD) [RFC6428] for Continuity
 Check / Connectivity Verification, the Delay Measurement (DM)
 protocol [RFC6374] for delay and delay variation (jitter)
 measurements, and the Loss Measurement (LM) protocol [RFC6374] for
 packet loss and throughput measurements.  Additionally, there are a
 number of Fault Management signals that can be configured [RFC6427].
 BFD is a protocol that provides low-overhead, fast detection of
 failures in the path between two forwarding engines, including the
 interfaces, data link(s), and (to the extent possible) the forwarding
 engines themselves.  BFD can be used to track the liveliness and to
 detect the data plane failures of MPLS-TP point to point and might
 also be extended to support point-to-multipoint connections.
 The delay and loss measurement protocols [RFC6374] use a simple
 query/response model for performing bidirectional measurements that
 allows the originating node to measure packet loss and delay in both
 directions.  By timestamping and/or writing current packet counters

Bellagamba, et al. Standards Track [Page 4] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 to the measurement packets four times (Tx and Rx in both directions),
 current delays and packet losses can be calculated.  By performing
 successive delay measurements, the delay variation (jitter) can be
 calculated.  Current throughput can be calculated from the packet
 loss measurements by dividing the number of packets sent/received
 with the time it took to perform the measurement, given by the
 timestamp in LM header.  Combined with a packet generator, the
 throughput measurement can be used to measure the maximum capacity of
 a particular LSP.  It should be noted that here we are not
 configuring on-demand throughput estimates based on saturating the
 connection as defined in [RFC6371].  Rather, we only enable the
 estimation of the current throughput based on loss measurements.

1.1. Conventions Used in This Document

1.1.1. Terminology

 AIS - Alarm Indication Signal
 BFD - Bidirectional Forwarding Detection
 CC - Continuity Check
 CV - Connectivity Verification
 DM - Delay Measurement
 FMS - Fault Management Signal
 G-ACh - Generic Associated Channel
 GMPLS - Generalized Multi-Protocol Label Switching
 LDI - Link Down Indication
 LER - Label Edge Router
 LKR - Lock Report
 LM - Loss Measurement
 LOC - Loss Of Continuity
 LSP - Label Switched Path
 LSR - Label Switching Router
 MEP - Maintenance Entity Group End Point

Bellagamba, et al. Standards Track [Page 5] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 MIP - Maintenance Entity Group Intermediate Point
 MPLS - Multi-Protocol Label Switching
 MPLS-TP - MPLS Transport Profile
 NMS - Network Management System
 PM - Performance Measurement
 RSVP-TE - Reservation Protocol Traffic Engineering
 TC - Traffic Class

1.1.2. Requirements Language

 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 RFC 2119 [RFC2119].

2. Overview of MPLS OAM for Transport Applications

 [RFC6371] describes how MPLS-TP OAM mechanisms are operated to meet
 transport requirements outlined in [RFC5860].
 [RFC6428] specifies two BFD operation modes: 1) "CC mode", which uses
 periodic BFD message exchanges with symmetric timer settings
 supporting Continuity Check, and 2) "CV/CC mode", which sends unique
 maintenance entity identifiers in the periodic BFD messages
 supporting CV as well as CC.
 [RFC6374] specifies mechanisms for Performance Monitoring of LSPs, in
 particular it specifies loss and delay measurement OAM functions.
 [RFC6427] specifies fault management signals with which a server LSP
 can notify client LSPs about various fault conditions to suppress
 alarms or to be used as triggers for actions in the client LSPs.  The
 following signals are defined: Alarm Indication Signal (AIS), Link
 Down Indication (LDI), and Lock Report (LKR).
 [RFC6371] describes the mapping of fault conditions to consequent
 actions.  Some of these mappings may be configured by the operator
 depending on the application of the LSP.  The following defects are
 identified: Loss Of Continuity (LOC), Misconnectivity, MEP
 Misconfiguration, and Period Misconfiguration.  Out of these defect
 conditions, the following consequent actions may be configurable: 1)

Bellagamba, et al. Standards Track [Page 6] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 whether or not the LOC defect should result in blocking the outgoing
 data traffic; 2) whether or not the "Period Misconfiguration defect"
 should result in a signal fail condition.

3. Theory of Operations

3.1. MPLS-TP OAM Configuration Operation Overview

 GMPLS RSVP-TE, or alternatively LSP Ping [LSP-PING-CONF], can be used
 to simply enable the different OAM functions by setting the
 corresponding flags in the OAM Function Flags Sub-TLV [RFC7260].  For
 a more detailed configuration, one may include sub-TLVs for the
 different OAM functions in order to specify various parameters in
 detail.
 Typically, intermediate nodes SHOULD NOT process or modify any of the
 OAM Configuration TLVs but simply forward them to the end node.
 There is one exception to this and that is if the MPLS OAM FMS Sub-
 TLV is present.  This sub-TLV MUST be examined even by intermediate
 nodes that support these extensions but only acted upon by nodes
 capable of transmitting FMS signals into the LSP being established.
 The sub-TLV MAY be present when the FMS flag is set in the OAM
 Function Flags Sub-TLV.  If this sub-TLV is present, then the "OAM
 MIP entities desired" and "OAM MEP entities desired" flags (described
 in [RFC7260]) in the LSP Attribute Flags TLV MUST be set and the
 entire OAM Configuration TLV placed either in the
 LSP_REQUIRED_ATTRIBUTES object or in the LSP_ATTRIBUTES object in
 order to ensure that capable intermediate nodes process the
 configuration.  If placed in the LSP_ATTRIBUTES object, nodes that
 are not able to process the OAM Configuration TLV will forward the
 message without generating an error.  If the MPLS OAM FMS Sub-TLV has
 been placed in the LSP_REQUIRED_ATTRIBUTES object, a node that
 supports RFC 7260 but does not support the MPLS OAM FMS Sub-TLV MUST
 generate a PathErr message with "OAM Problem/Configuration Error"
 [RFC7260].  Otherwise, if the node doesn't support RFC 7260, it will
 not raise any errors as described in the Section 4.1 of [RFC7260].
 Finally, if the MPLS OAM FMS Sub-TLV is not included, only the "OAM
 MEP entities desired" flag is set and the OAM Configuration TLV may
 be placed in either LSP_ATTRIBUTES or LSP_REQUIRED_ATTRIBUTES.

Bellagamba, et al. Standards Track [Page 7] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

3.1.1. Configuration of BFD Sessions

 For this specification, BFD MUST be run in either one of the two
 modes:
 o  Asynchronous mode, where both sides should be in active mode; or
 o  Unidirectional mode.
 In the simplest scenario, RSVP-TE (or alternatively LSP Ping
 [LSP-PING-CONF]), is used only to bootstrap a BFD session for an LSP
 without any timer negotiation.
 Timer negotiation can be performed either in subsequent BFD Control
 messages (in this case the operation is similar to LSP-Ping-based
 bootstrapping described in [RFC5884]) or directly in the RSVP-TE
 signaling messages.
 When BFD Control packets are transported in the G-ACh, they are not
 protected by any end-to-end checksum; only lower layers are providing
 error detection/correction.  A single bit error, e.g., a flipped bit
 in the BFD State field, could cause the receiving end to wrongly
 conclude that the link is down and, in turn, trigger protection
 switching.  To prevent this from happening, the BFD Configuration
 Sub-TLV has an Integrity flag that, when set, enables BFD
 Authentication using Keyed SHA1 with an empty key (all 0s) [RFC5880].
 This would ensure that every BFD Control packet carries a SHA1 hash
 of itself that can be used to detect errors.
 If BFD Authentication using a pre-shared key / password is desired
 (i.e., authentication and not only error detection), the BFD
 Authentication Sub-TLV MUST be included in the BFD Configuration Sub-
 TLV.  The BFD Authentication Sub-TLV is used to specify which
 authentication method should be used and which pre-shared key /
 password should be used for this particular session.  How the key
 exchange is performed is out of scope of this document.

3.1.2. Configuration of Performance Monitoring

 It is possible to configure Performance Monitoring functionalities
 such as Loss, Delay, Delay variation (jitter), and Throughput, as
 described in [RFC6374].
 When configuring Performance Monitoring functionalities, it is
 possible to choose either the default configuration (by only setting
 the respective flags in the OAM Function Flags Sub-TLV) or a

Bellagamba, et al. Standards Track [Page 8] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 customized configuration.  To customize the configuration, one would
 set the respective flags and include the respective Loss and/or Delay
 sub-TLVs.
 By setting the PM/Loss flag in the OAM Function Flags Sub-TLV and by
 including the MPLS OAM PM Loss Sub-TLV, one can configure the
 measurement interval and loss threshold values for triggering
 protection.
 Delay measurements are configured by setting the PM/Delay flag in the
 OAM Function Flags Sub-TLV; by including the MPLS OAM PM Loss Sub-
 TLV, one can configure the measurement interval and the delay
 threshold values for triggering protection.

3.1.3. Configuration of Fault Management Signals

 To configure Fault Management signals and their refresh time, the FMS
 flag in the OAM Function Flags Sub-TLV MUST be set and the MPLS OAM
 FMS Sub-TLV included.  When configuring Fault Management signals, an
 implementation can enable the default configuration by setting the
 FMS flag in the OAM Function Flags Sub-TLV.  In order to modify the
 default configuration, the MPLS OAM FMS Sub-TLV MUST be included.
 If an intermediate point is intended to originate fault management
 signal messages, this means that such an intermediate point is
 associated with a server MEP through a co-located MPLS-TP client/
 server adaptation function, and the "Fault Management subscription"
 flag in the MPLS OAM FMS Sub-TLV has been set as an indication of the
 request to create the association at each intermediate node of the
 client LSP.  The corresponding server MEP needs to be configured by
 its own RSVP-TE session (or, alternatively, via an NMS or LSP Ping).

3.2. MPLS OAM Configuration Sub-TLV

 The OAM Configuration TLV, defined in [RFC7260], specifies the OAM
 functions that are used for the LSP.  This document extends the OAM
 Configuration TLV by defining a new OAM Type: "MPLS OAM" (3).  The
 MPLS OAM type is set to request the establishment of OAM functions
 for MPLS-TP LSPs.  The specific OAM functions are specified in the
 OAM Function Flags Sub-TLV as depicted in [RFC7260].
 When an egress LSR receives an OAM Configuration TLV indicating the
 MPLS OAM type, the LSR will first process any present OAM Function
 Flags Sub-TLV, and then it MUST process technology-specific
 configuration TLVs.  This document defines a sub-TLV, the MPLS OAM
 Configuration Sub-TLV, which is carried in the OAM Configuration TLV.

Bellagamba, et al. Standards Track [Page 9] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | MPLS OAM Conf. Sub-TLV (33)   |            Length             |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                                                               |
 ~                           sub-TLVs                            ~
 |                                                               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            Figure 1: MPLS OAM Configuration Sub-TLV Format
 Type: 33, the MPLS OAM Configuration Sub-TLV.
 Length: Indicates the total length in octets, including sub-TLVs as
 well as the Type and Length fields.
 The following MPLS-OAM-specific sub-TLVs MAY be included in the MPLS
 OAM Configuration Sub-TLV:
 o  BFD Configuration Sub-TLV MUST be included if either the CC, the
    CV, or both OAM Function flags are being set in the OAM Function
    Flags Sub-TLV [RFC7260].  This sub-TLV carries additional sub-
    TLVs; failure to include the correct sub-TLVs MUST result in an
    error being generated: "OAM Problem/Configuration Error".  The
    sub-TLVs are:
  • BFD Identifiers Sub-TLV MUST always be included.
  • Timer Negotiation Parameters Sub-TLV MUST be included if the N

flag is not set.

  • BFD Authentication Sub-TLV MAY be included if the I flag is

set.

 o  Performance Monitoring Sub-TLV, which MUST be included if any of
    the PM/Delay, PM/Loss, or PM/Throughput flags are set in the OAM
    Function Flag Sub-TLV [RFC7260].  This sub-TLV MAY carry
    additional sub-TLVs:
  • MPLS OAM PM Loss Sub-TLV MAY be included if the PM/Loss OAM

Function flag is set. If the MPLS OAM PM Loss Sub-TLV is not

       included, default configuration values are used.  The same sub-
       TLV MAY also be included in case the PM/Throughput OAM Function
       flag is set and there is the need to specify measurement
       intervals different from the default ones.  Since throughput
       measurements use the same tool as loss measurements, the same
       TLV is used.

Bellagamba, et al. Standards Track [Page 10] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

  • MPLS OAM PM Delay Sub-TLV MAY be included if the PM/Delay OAM

Function flag is set. If the MPLS OAM PM Delay Sub-TLV is not

       included, default configuration values are used.
 o  MPLS OAM FMS Sub-TLV MAY be included if the FMS OAM Function flag
    is set.  If the MPLS OAM FMS Sub-TLV is not included, default
    configuration values are used.
 The following are some additional rules of processing the MPLS OAM
 Configuration Sub-TLV:
 o  The MPLS OAM Configuration Sub-TLV MAY be empty, i.e., have no
    Value.  If so, then its Length MUST be 8.  Then, all OAM functions
    that have their corresponding flags set in the OAM Function Flags
    Sub-TLV MUST be assigned their default values or left disabled.
 o  A sub-TLV that doesn't have a corresponding flag set MUST be
    silently ignored.
 o  If multiple copies of a sub-TLV are present, then only the first
    sub-TLV MUST be used and the remaining sub-TLVs MUST be silently
    ignored.
 However, not all the values can be derived from the standard RSVP-TE
 objects, in particular the locally assigned Tunnel ID at the egress
 cannot be derived by the ingress node.  Therefore, the full LSP MEP-
 ID used by the ingress has to be carried in the BFD Identifiers Sub-
 TLV in the Path message and the egress LSP MEP-ID in the same way in
 the Resv message.

3.2.1. CV Flag Rules of Use

 If the CV flag is set in the OAM Function Flags Sub-TLV [RFC7260],
 then the CC flag MUST be set as well because performing Connectivity
 Verification implies performing Continuity Check as well.  The format
 of an MPLS-TP CV/CC message is shown in [RFC6428].  In order to
 perform Connectivity Verification, the CV/CC message MUST contain the
 "LSP MEP-ID" in addition to the BFD Control packet information.  The
 "LSP MEP-ID" contains four identifiers:
    MPLS-TP Global_ID
    MPLS-TP Node Identifier
    Tunnel_Num
    LSP_Num

Bellagamba, et al. Standards Track [Page 11] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 These values need to be correctly set by both ingress and egress when
 transmitting a CV packet, and both ingress and egress need to know
 what to expect when receiving a CV packet.  Most of these values can
 be derived from the Path and Resv messages [RFC3473], which use a
 5-tuple to uniquely identify an LSP within an operator's network.
 This tuple is composed of a Tunnel Sender Address, Tunnel Endpoint
 Address, Tunnel_ID, Extended Tunnel ID, and (GMPLS) LSP_ID.

3.3. BFD Configuration Sub-TLV

 The BFD Configuration Sub-TLV (depicted below) is defined for BFD-
 OAM-specific configuration parameters.  The BFD Configuration Sub-TLV
 is carried as a sub-TLV of the MPLS OAM Configuration Sub-TLV.
 This TLV accommodates generic BFD OAM information and carries sub-
 TLVs.
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      BFD Conf. Type (1)       |           Length              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |Vers.|N|S|I|G|U|B|       Reserved (set to all 0s)              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                                                               |
 ~                           sub-TLVs                            ~
 |                                                               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
              Figure 2: BFD Configuration Sub-TLV Format
 Type: 1, the BFD Configuration Sub-TLV.
 Length: Indicates the total length in octets, including sub-TLVs as
 well as the Type and Length fields.
 Version: Identifies the BFD protocol version.  If the egress LSR does
 not support the version, an error MUST be generated: "OAM Problem/
 Unsupported BFD Version".
 BFD Negotiation (N): If set timer negotiation/re-negotiation via BFD
 Control messages is enabled, when cleared it is disabled.
 Symmetric Session (S): If set, the BFD session MUST use symmetric
 timing values.

Bellagamba, et al. Standards Track [Page 12] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 Integrity (I): If set, BFD Authentication MUST be enabled.  If the
 BFD Configuration Sub-TLV does not include a BFD Authentication Sub-
 TLV, the authentication MUST use Keyed SHA1 with an empty pre-shared
 key (all 0s).  If the egress LSR does not support BFD Authentication,
 an error MUST be generated: "OAM Problem/BFD Authentication
 unsupported".
 Encapsulation Capability (G): If set, it shows the capability of
 encapsulating BFD messages into The G-Ach channel.  If both the G bit
 and U bit are set, configuration gives precedence to the G bit.  If
 the egress LSR does not support any of the ingress LSR Encapsulation
 Capabilities, an error MUST be generated: "OAM Problem/Unsupported
 BFD Encapsulation format".
 Encapsulation Capability (U): If set, it shows the capability of
 encapsulating BFD messages into UDP packets.  If both the G bit and U
 bit are set, configuration gives precedence to the G bit.  If the
 egress LSR does not support any of the ingress LSR Encapsulation
 Capabilities, an error MUST be generated: "OAM Problem/Unsupported
 BFD Encapsulation Format".
 Bidirectional (B): If set, it configures BFD in the Bidirectional
 mode.  If it is not set, it configures BFD in unidirectional mode.
 In the second case, the source node does not expect any Discriminator
 values back from the destination node.
 Reserved: Reserved for future specifications; set to 0 on
 transmission and ignored when received.
 The BFD Configuration Sub-TLV MUST include the following sub-TLVs in
 the Path message:
 o  BFD Identifiers Sub-TLV; and
 o  Negotiation Timer Parameters Sub-TLV if the N flag is cleared.
 The BFD Configuration Sub-TLV MUST include the following sub-TLVs in
 the Resv message:
 o  BFD Identifiers Sub-TLV; and
 o  Negotiation Timer Parameters Sub-TLV if:
  • the N and S flags are cleared; or if

Bellagamba, et al. Standards Track [Page 13] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

  • the N flag is cleared and the S flag is set and the Negotiation

Timer Parameters Sub-TLV received by the egress contains

       unsupported values.  In this case, an updated Negotiation Timer
       Parameters Sub-TLV containing values supported by the egress
       LSR MUST be returned to the ingress.

3.3.1. BFD Identifiers Sub-TLV

 The BFD Identifiers Sub-TLV is carried as a sub-TLV of the BFD
 Configuration Sub-TLV and is depicted below.
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |   BFD Identifiers Type (1)    |            Length             |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                     Local Discriminator                       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                       MPLS-TP Global_ID                       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                    MPLS-TP Node Identifier                    |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |           Tunnel_Num          |            LSP_Num            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
               Figure 3: BFD Identifiers Sub-TLV Format
 Type: 1, the BFD Identifiers Sub-TLV.
 Length: Indicates the TLV total length in octets, including the Type
 and Length fields (20).
 Local Discriminator: A unique, non-zero discriminator value generated
 by the transmitting system and referring to itself; it is used to de-
 multiplex multiple BFD sessions between the same pair of systems as
 defined in [RFC5880].
 MPLS-TP Global_ID, Node Identifier, Tunnel_Num, and LSP_Num: All set
 as defined in [RFC6370].

Bellagamba, et al. Standards Track [Page 14] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

3.3.2. Negotiation Timer Parameters Sub-TLV

 The Negotiation Timer Parameters Sub-TLV is carried as a sub-TLV of
 the BFD Configuration Sub-TLV and is depicted below.
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |    Nego. Timer Type (2)       |             Length            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Acceptable Min. Asynchronous TX interval              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         Acceptable Min. Asynchronous RX interval              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |               Required Echo TX Interval                       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
         Figure 4: Negotiation Timer Parameters Sub-TLV Format
 Type: 2, the Negotiation Timer Parameters Sub-TLV.
 Length: Indicates the TLV total length in octets, including Type and
 Length fields (16).
 Acceptable Min. Asynchronous TX interval: If the S flag is set in the
 BFD Configuration Sub-TLV, it expresses the desired time interval (in
 microseconds) at which the ingress LER intends to both transmit and
 receive BFD periodic control packets.  If the egress LSR cannot
 support the value, it SHOULD reply with a supported interval.
 If the S flag is cleared in the BFD Configuration Sub-TLV, this field
 expresses the desired time interval (in microseconds) at which the
 ingress LSR intends to transmit BFD periodic control packets.
 Acceptable Min. Asynchronous RX interval: If the S flag is set in the
 BFD Configuration Sub-TLV, this field MUST be set equal to
 "Acceptable Min. Asynchronous TX interval" on transmit and MUST be
 ignored on receipt since it has no additional meaning with respect to
 the one described for "Acceptable Min. Asynchronous TX interval".
 If the S flag is cleared in the BFD Configuration Sub-TLV, it
 expresses the minimum time interval (in microseconds) at which the
 ingress/egress LSRs can receive periodic BFD Control packets.  If
 this value is greater than the "Acceptable Min. Asynchronous TX
 interval" received from the ingress/egress LSR, the receiving LSR
 MUST adopt the interval expressed in the "Acceptable Min.
 Asynchronous RX interval".

Bellagamba, et al. Standards Track [Page 15] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 Required Echo TX Interval: The minimum interval (in microseconds)
 between received BFD Echo packets that this system is capable of
 supporting, less any jitter applied by the sender as described in
 Section 6.8.9 of [RFC5880].  This value is also an indication for the
 receiving system of the minimum interval between transmitted BFD Echo
 packets.  If this value is zero, the transmitting system does not
 support the receipt of BFD Echo packets.  If the LSR node cannot
 support this value, it SHOULD reply with a supported value (which may
 be zero if Echo is not supported).

3.3.3. BFD Authentication Sub-TLV

 The BFD Authentication Sub-TLV is carried as a sub-TLV of the BFD
 Configuration Sub-TLV and is depicted below.
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      BFD Auth. Type (3)       |            Length             |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |   Auth Type   |  Auth Key ID  |         Reserved (0s)         |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
              Figure 5: BFD Authentication Sub-TLV Format
 Type: 3, the BFD Authentication Sub-TLV.
 Length: Indicates the TLV total length in octets, including Type and
 Length fields (8).
 Auth Type: Indicates which type of authentication to use.  The same
 values are used as are defined in Section 4.1 of [RFC5880].  If the
 egress LSR does not support this type, an "OAM Problem/Unsupported
 BFD Authentication Type" error MUST be generated.
 Auth Key ID: Indicates which authentication key or password
 (depending on Auth Type) should be used.  How the key exchange is
 performed is out of scope of this document.  If the egress LSR does
 not support this Auth Key ID, an "OAM Problem/Mismatch of BFD
 Authentication Key ID" error MUST be generated.
 Reserved: Reserved for future specifications; set to 0 on
 transmission and ignored when received.

Bellagamba, et al. Standards Track [Page 16] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

3.3.4. Traffic Class Sub-TLV

 The Traffic Class Sub-TLV is carried as a sub-TLV of the BFD
 Configuration Sub-TLV or Fault Management Signal Sub-TLV
 (Section 3.5) and is depicted in Figure 6.
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |  Traffic Class Sub-Type (4)   |            Length             |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |  TC |                 Reserved (set to all 0s)                |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                Figure 6: Traffic Class Sub-TLV Format
 Type: 4, the Traffic Class Sub-TLV.
 Length: Indicates the length of the Value field in octets (4).
 Traffic Class (TC): Identifies the TC [RFC5462] for periodic
 continuity monitoring messages or packets with fault management
 information.
 If the Traffic Class Sub-TLV is present, then the value of the TC
 field MUST be used as the value of the TC field of an MPLS label
 stack entry.  If the Traffic Class Sub-TLV is absent from BFD
 Configuration Sub-TLV or Fault Management Signal Sub-TLV, then
 selection of the TC value is a local decision.

3.4. Performance Monitoring Sub-TLV

 If the OAM Function Flags Sub-TLV has either the PM/Loss, PM/Delay,
 or PM/Throughput flag set, the Performance Monitoring Sub-TLV MUST be
 present in the MPLS OAM Configuration Sub-TLV.  Failure to include
 the correct sub-TLVs MUST result in an "OAM Problem/Configuration
 Error" message being generated.
 The Performance Monitoring Sub-TLV provides the configuration
 information mentioned in Section 7 of [RFC6374].  It includes support
 for the configuration of quality thresholds and, as described in
 [RFC6374], "the crossing of which will trigger warnings or alarms,
 and result reporting and exception notification will be integrated
 into the system-wide network management and reporting framework."

Bellagamba, et al. Standards Track [Page 17] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 In case the values need to be different than the default ones, the
 Performance Monitoring Sub-TLV includes the following sub-TLVs:
 o  MPLS OAM PM Loss Sub-TLV if the PM/Loss and/or PM/Throughput flag
    is set in the OAM Function Flags Sub-TLV; and
 o  MPLS OAM PM Delay Sub-TLV if the PM/Delay flag is set in the OAM
    Function Flags Sub-TLV.
 The Performance Monitoring Sub-TLV depicted below is carried as a
 sub-TLV of the MPLS OAM Configuration Sub-TLV.
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |    Perf. Monitoring Type (2)  |          Length               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |D|L|J|Y|K|C|            Reserved (set to all 0s)               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                                                               |
 ~                           sub-TLVs                            ~
 |                                                               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
            Figure 7: Performance Monitoring Sub-TLV Format
 Type: 2, the Performance Monitoring Sub-TLV.
 Length: Indicates the TLV total length in octets, including sub-TLVs
 as well as Type and Length fields.
 Configuration Flags (for the specific function description please
 refer to [RFC6374]):
 o  D: Delay inferred/direct (0=INFERRED, 1=DIRECT).  If the egress
    LSR does not support the specified mode, an "OAM Problem/
    Unsupported Delay Mode" error MUST be generated.
 o  L: Loss inferred/direct (0=INFERRED, 1=DIRECT).  If the egress LSR
    does not support the specified mode, an "OAM Problem/Unsupported
    Loss Mode" error MUST be generated.
 o  J: Delay variation/jitter (1=ACTIVE, 0=NOT ACTIVE).  If the egress
    LSR does not support Delay variation measurements and the J flag
    is set, an "OAM Problem/Delay variation unsupported" error MUST be
    generated.

Bellagamba, et al. Standards Track [Page 18] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 o  Y: Dyadic (1=ACTIVE, 0=NOT ACTIVE).  If the egress LSR does not
    support Dyadic mode and the Y flag is set, an "OAM Problem/Dyadic
    mode unsupported" error MUST be generated.
 o  K: Loopback (1=ACTIVE, 0=NOT ACTIVE).  If the egress LSR does not
    support Loopback mode and the K flag is set, an "OAM Problem/
    Loopback mode unsupported" error MUST be generated.
 o  C: Combined (1=ACTIVE, 0=NOT ACTIVE).  If the egress LSR does not
    support Combined mode and the C flag is set, an "OAM Problem/
    Combined mode unsupported" error MUST be generated.
 Reserved: Reserved for future specifications; set to 0 on
 transmission and ignored when received.

3.4.1. MPLS OAM PM Loss Sub-TLV

 The MPLS OAM PM Loss Sub-TLV depicted below is carried as a sub-TLV
 of the Performance Monitoring Sub-TLV.
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |       PM Loss Type (1)        |          Length               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | OTF |T|B|              Reserved (set to all 0s)               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                    Measurement Interval                       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                       Test Interval                           |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                      Loss Threshold                           |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
               Figure 8: MPLS OAM PM Loss Sub-TLV Format
 Type: 1, the MPLS OAM PM Loss Sub-TLV.
 Length: Indicates the length of the parameters in octets, including
 Type and Length fields (20).
 Origin Timestamp Format (OTF): Origin Timestamp Format of the Origin
 Timestamp field described in [RFC6374].  By default, it is set to
 IEEE 1588 version 1.  If the egress LSR cannot support this value, an
 "OAM Problem/Unsupported Timestamp Format" error MUST be generated.

Bellagamba, et al. Standards Track [Page 19] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 Configuration Flags (please refer to [RFC6374] for further details):
 o  T: Traffic-class-specific measurement indicator.  Set to 1 when
    the measurement operation is scoped to packets of a particular
    traffic class (Differentiated Service Code Point (DSCP) value) and
    zero otherwise.  When set to 1, the Differentiated Services (DS)
    field of the message indicates the measured traffic class.  By
    default, it is set to 1.
 o  B: Octet (byte) count.  When set to 1, it indicates that the
    Counter 1-4 fields represent octet counts.  When set to 0, it
    indicates that the Counter 1-4 fields represent packet counts.  By
    default, it is set to 0.
 Reserved: Reserved for future specifications; set to 0 on
 transmission and ignored when received.
 Measurement Interval: The time interval (in milliseconds) at which
 Loss Measurement query messages MUST be sent in both directions.  If
 the egress LSR cannot support the value, it SHOULD reply with a
 supported interval.  By default, it is set to 100 milliseconds as per
 [RFC6375].
 Test Interval: Test messages interval (in milliseconds) as described
 in [RFC6374].  By default, it is set to 10 milliseconds as per
 [RFC6375].  If the egress LSR cannot support the value, it SHOULD
 reply with a supported interval.
 Loss Threshold: The threshold value of measured lost packets per
 measurement over which action(s) SHOULD be triggered.

Bellagamba, et al. Standards Track [Page 20] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

3.4.2. MPLS OAM PM Delay Sub-TLV

 The MPLS OAM PM Delay Sub-TLV depicted below is carried as a sub-TLV
 of the Performance Monitoring Sub-TLV.
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      PM Delay Type (2)        |          Length               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | OTF |T|B|             Reserved (set to all 0s)                |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                    Measurement Interval                       |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                       Test Interval                           |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                      Delay Threshold                          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
              Figure 9: MPLS OAM PM Delay Sub-TLV Format
 Type: 2, the MPLS OAM PM Delay Sub-TLV.
 Length: Indicates the length of the parameters in octets, including
 Type and Length fields (20).
 OTF: Origin Timestamp Format of the Origin Timestamp field described
 in [RFC6374].  By default, it is set to IEEE 1588 version 1.  If the
 egress LSR cannot support this value, an "OAM Problem/Unsupported
 Timestamp Format" error MUST be generated.
 Configuration Flags (please refer to [RFC6374] for further details):
 o  T: Traffic-class-specific measurement indicator.  Set to 1 when
    the measurement operation is scoped to packets of a particular
    traffic class (Differentiated Services Code Point (DSCP) value)
    and zero otherwise.  When set to 1, the Differentiated Service
    (DS) field of the message indicates the measured traffic class.
    By default, it is set to 1.
 o  B: Octet (byte) count.  When set to 1, it indicates that the
    Counter 1-4 fields represent octet counts.  When set to 0, it
    indicates that the Counter 1-4 fields represent packet counts.  By
    default, it is set to 0.
 Reserved: Reserved for future specifications; set to 0 on
 transmission and ignored when received.

Bellagamba, et al. Standards Track [Page 21] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 Measurement Interval: The time interval (in milliseconds) at which
 Delay Measurement query messages MUST be sent on both directions.  If
 the egress LSR cannot support the value, it SHOULD reply with a
 supported interval.  By default, it is set to 1000 milliseconds as
 per [RFC6375].
 Test Interval: Test messages interval (in milliseconds) as described
 in [RFC6374].  By default, it is set to 10 milliseconds as per
 [RFC6375].  If the egress LSR cannot support the value, it SHOULD
 reply with a supported interval.
 Delay Threshold: The threshold value of measured two-way delay (in
 milliseconds) over which action(s) SHOULD be triggered.

3.5. MPLS OAM FMS Sub-TLV

 The MPLS OAM FMS Sub-TLV depicted below is carried as a sub-TLV of
 the MPLS OAM Configuration Sub-TLV.  When both working and protection
 paths are signaled, both LSPs SHOULD be signaled with identical
 settings of the E flag, T flag, and the refresh timer.
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |     MPLS OAM FMS Type (3)     |            Length             |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |E|S|T|           Reserved            |      Refresh Timer      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                                                               |
 ~                           Sub-TLVs                            ~
 |                                                               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                Figure 10: MPLS OAM FMS Sub-TLV Format
 Type: 3, the MPLS OAM FMS Sub-TLV.
 Length: Indicates the TLV total length in octets, including Type and
 Length fields (8).
 FMS Signal Flags are used to enable the FMS signals at MEPs and the
 server MEPs of the links over which the LSP is forwarded.  In this
 document, only the S flag pertains to server MEPs.

Bellagamba, et al. Standards Track [Page 22] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 The following flags are defined:
    E: Enable Alarm Indication Signal (AIS) and Lock Report (LKR)
    signaling as described in [RFC6427].  The default value is 1
    (enabled).  If the egress MEP does not support FMS signal
    generation, an "OAM Problem/Fault management signaling
    unsupported" error MUST be generated.
    S: Indicate to a server MEP that it should transmit AIS and LKR
    signals on client LSPs.  The default value is 0 (disabled).  If a
    server MEP, which is capable of generating FMS messages, is for
    some reason unable to do so for the LSP being signaled an "OAM
    Problem/Unable to create fault management association" error MUST
    be generated.
    T: Set timer value, enabled by the configuration of a specific
    timer value.  The Default value is 0 (disabled).
    Remaining bits: Reserved for a future specification and set to 0.
 Refresh Timer: Indicates (in seconds) the refresh timer of fault
 indication messages.  The value MUST be between 1 to 20 seconds as
 specified for the Refresh Timer field in [RFC6427].  If the egress
 LSR cannot support the value, it SHOULD reply with a supported timer
 value.
 The Fault Management Signals Sub-TLV MAY include the Traffic Class
 Sub-TLV (Section 3.3.4.)  If the Traffic Class Sub-TLV is present,
 the value of the TC field MUST be used as the value of the TC field
 of an MPLS label stack entry for FMS messages.  If the Traffic Class
 Sub-TLV is absent, then selection of the TC value is local decision.

4. Summary of MPLS OAM Configuration Errors

 In addition to error values specified in [RFC7260], this document
 defines the following values for the "OAM Problem" error code:
 o  If an egress LSR does not support the specified BFD version, an
    error MUST be generated: "OAM Problem/Unsupported BFD Version".
 o  If an egress LSR does not support the specified BFD Encapsulation
    format, an error MUST be generated: "OAM Problem/Unsupported BFD
    Encapsulation format".
 o  If an egress LSR does not support BFD Authentication and it is
    requested, an error MUST be generated: "OAM Problem/BFD
    Authentication unsupported".

Bellagamba, et al. Standards Track [Page 23] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 o  If an egress LSR does not support the specified BFD Authentication
    Type, an error MUST be generated: "OAM Problem/Unsupported BFD
    Authentication Type".
 o  If an egress LSR is not able to use the specified Authentication
    Key ID, an error MUST be generated: "OAM Problem/Mismatch of BFD
    Authentication Key ID".
 o  If an egress LSR does not support the specified Timestamp Format,
    an error MUST be generated: "OAM Problem/Unsupported Timestamp
    Format".
 o  If an egress LSR does not support the specified Delay mode, an
    "OAM Problem/Unsupported Delay Mode" error MUST be generated.
 o  If an egress LSR does not support the specified Loss mode, an "OAM
    Problem/Unsupported Loss Mode" error MUST be generated.
 o  If an egress LSR does not support Delay variation measurements and
    it is requested, an "OAM Problem/Delay variation unsupported"
    error MUST be generated.
 o  If an egress LSR does not support Dyadic mode and it is requested,
    an "OAM Problem/Dyadic mode unsupported" error MUST be generated.
 o  If an egress LSR does not support Loopback mode and it is
    requested, an "OAM Problem/Loopback mode unsupported" error MUST
    be generated.
 o  If an egress LSR does not support Combined mode and it is
    requested, an "OAM Problem/Combined mode unsupported" error MUST
    be generated.
 o  If an egress LSR does not support Fault Monitoring signals and it
    is requested, an "OAM Problem/Fault management signaling
    unsupported" error MUST be generated.
 o  If an intermediate server MEP supports Fault Monitoring signals
    but is unable to create an association when requested to do so, an
    "OAM Problem/Unable to create fault management association" error
    MUST be generated.

Bellagamba, et al. Standards Track [Page 24] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

5. IANA Considerations

5.1. MPLS OAM Type

 This document specifies the new MPLS OAM type.  IANA has allocated a
 new type (3) from the "OAM Types" space of the "RSVP-TE OAM
 Configuration Registry".
                  +------+-------------+-----------+
                  | Type | Description | Reference |
                  +------+-------------+-----------+
                  |  3   |   MPLS OAM  | [RFC7487] |
                  +------+-------------+-----------+
                        Table 1: MPLS OAM Type

5.2. MPLS OAM Configuration Sub-TLV

 This document specifies the MPLS OAM Configuration Sub-TLV.  IANA has
 allocated a new type (33) from the OAM Sub-TLV space of the "RSVP-TE
 OAM Configuration Registry".
         +------+--------------------------------+-----------+
         | Type |          Description           | Reference |
         +------+--------------------------------+-----------+
         |  33  | MPLS OAM Configuration Sub-TLV | [RFC7487] |
         +------+--------------------------------+-----------+
             Table 2: MPLS OAM Configuration Sub-TLV Type

Bellagamba, et al. Standards Track [Page 25] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

5.3. MPLS OAM Configuration Sub-TLV Types

 IANA has created an "MPLS OAM Configuration Sub-TLV Types" sub-
 registry in the "RSVP-TE OAM Configuration Registry" for the sub-TLVs
 carried in the MPLS OAM Configuration Sub-TLV.  Values from this new
 sub-registry are to be allocated through IETF Review except for the
 "Reserved for Experimental Use" range.  This document defines the
 following types:
     +-------------+--------------------------------+-----------+
     |     Type    |          Description           | Reference |
     +-------------+--------------------------------+-----------+
     |      0      |            Reserved            | [RFC7487] |
     |      1      |   BFD Configuration Sub-TLV    | [RFC7487] |
     |      2      | Performance Monitoring Sub-TLV | [RFC7487] |
     |      3      |      MPLS OAM FMS Sub-TLV      | [RFC7487] |
     |   4-65532   |           Unassigned           |           |
     | 65533-65534 | Reserved for Experimental Use  | [RFC7487] |
     |    65535    |            Reserved            | [RFC7487] |
     +-------------+--------------------------------+-----------+
             Table 3: MPLS OAM Configuration Sub-TLV Types

5.4. BFD Configuration Sub-TLV Types

 IANA has created a "BFD Configuration Sub-TLV Types" sub-registry in
 the "RSVP-TE OAM Configuration Registry" for the sub-TLV types
 carried in the BFD Configuration Sub-TLV.  Values from this new sub-
 registry are to be allocated through IETF Review except for the
 "Reserved for Experimental Use" range.  This document defines the
 following types:
  +-------------+--------------------------------------+-----------+
  |     Type    |             Description              | Reference |
  +-------------+--------------------------------------+-----------+
  |      0      |               Reserved               | [RFC7487] |
  |      1      |       BFD Identifiers Sub-TLV        | [RFC7487] |
  |      2      | Negotiation Timer Parameters Sub-TLV | [RFC7487] |
  |      3      |      BFD Authentication Sub-TLV      | [RFC7487] |
  |      4      |        Traffic Class Sub-TLV         | [RFC7487] |
  |   5-65532   |              Unassigned              |           |
  | 65533-65534 |    Reserved for Experimental Use     | [RFC7487] |
  |    65535    |               Reserved               | [RFC7487] |
  +-------------+--------------------------------------+-----------+
               Table 4: BFD Configuration Sub-TLV Types

Bellagamba, et al. Standards Track [Page 26] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

5.5. Performance Monitoring Sub-TLV Types

 IANA has created a "Performance Monitoring Sub-TLV Type" sub-registry
 in the "RSVP-TE OAM Configuration Registry" for the sub-TLV types
 carried in the Performance Monitoring Sub-TLV.  Values from this new
 sub-registry are to be allocated through IETF Review except for the
 "Reserved for Experimental Use" range.  This document defines the
 following types:
      +-------------+-------------------------------+-----------+
      |     Type    |          Description          | Reference |
      +-------------+-------------------------------+-----------+
      |      0      |            Reserved           | [RFC7487] |
      |      1      |    MPLS OAM PM Loss Sub-TLV   | [RFC7487] |
      |      2      |   MPLS OAM PM Delay Sub-TLV   | [RFC7487] |
      |   3-65532   |           Unassigned          |           |
      | 65533-65534 | Reserved for Experimental Use | [RFC7487] |
      |    65535    |            Reserved           | [RFC7487] |
      +-------------+-------------------------------+-----------+
             Table 5: Performance Monitoring Sub-TLV Types

Bellagamba, et al. Standards Track [Page 27] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

5.6. New RSVP-TE Error Codes

 The following values have been assigned under the "OAM Problem" error
 code [RFC7260] by IETF Review process:
 +------------------+------------------------------------+-----------+
 | Error Value Sub- | Description                        | Reference |
 | Codes            |                                    |           |
 +------------------+------------------------------------+-----------+
 | 13               | Unsupported BFD Version            | [RFC7487] |
 | 14               | Unsupported BFD Encapsulation      | [RFC7487] |
 |                  | format                             |           |
 | 15               | Unsupported BFD Authentication     | [RFC7487] |
 |                  | Type                               |           |
 | 16               | Mismatch of BFD Authentication Key | [RFC7487] |
 |                  | ID                                 |           |
 | 17               | Unsupported Timestamp Format       | [RFC7487] |
 | 18               | Unsupported Delay Mode             | [RFC7487] |
 | 19               | Unsupported Loss Mode              | [RFC7487] |
 | 20               | Delay variation unsupported        | [RFC7487] |
 | 21               | Dyadic mode unsupported            | [RFC7487] |
 | 22               | Loopback mode unsupported          | [RFC7487] |
 | 23               | Combined mode unsupported          | [RFC7487] |
 | 24               | Fault management signaling         | [RFC7487] |
 |                  | unsupported                        |           |
 | 25               | Unable to create fault management  | [RFC7487] |
 |                  | association                        |           |
 +------------------+------------------------------------+-----------+
              Table 6: MPLS OAM Configuration Error Codes
 The "Sub-Codes - 40 OAM Problem" sub-registry is located in the
 "Error Codes and Globally-Defined Error Value Sub-Codes" registry.

6. Security Considerations

 The signaling of OAM-related parameters and the automatic
 establishment of OAM entities introduces additional security
 considerations to those discussed in [RFC3473].  In particular, a
 network element could be overloaded if an attacker were to request
 high frequency liveliness monitoring of a large number of LSPs,
 targeting a single network element as discussed in [RFC7260] and
 [RFC6060].
 Additional discussion of security for MPLS and GMPLS protocols can be
 found in [RFC5920].

Bellagamba, et al. Standards Track [Page 28] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

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>.
 [RFC3473]  Berger, L., Ed., "Generalized Multi-Protocol Label
            Switching (GMPLS) Signaling Resource ReserVation Protocol-
            Traffic Engineering (RSVP-TE) Extensions", RFC 3473,
            January 2003, <http://www.rfc-editor.org/info/rfc3473>.
 [RFC5654]  Niven-Jenkins, B., Ed., Brungard, D., Ed., Betts, M., Ed.,
            Sprecher, N., and S. Ueno, "Requirements of an MPLS
            Transport Profile", RFC 5654, September 2009,
            <http://www.rfc-editor.org/info/rfc5654>.
 [RFC5860]  Vigoureux, M., Ed., Ward, D., Ed., and M. Betts, Ed.,
            "Requirements for Operations, Administration, and
            Maintenance (OAM) in MPLS Transport Networks", RFC 5860,
            May 2010, <http://www.rfc-editor.org/info/rfc5860>.
 [RFC5880]  Katz, D. and D. Ward, "Bidirectional Forwarding Detection
            (BFD)", RFC 5880, June 2010,
            <http://www.rfc-editor.org/info/rfc5880>.
 [RFC5884]  Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow,
            "Bidirectional Forwarding Detection (BFD) for MPLS Label
            Switched Paths (LSPs)", RFC 5884, June 2010,
            <http://www.rfc-editor.org/info/rfc5884>.
 [RFC6060]  Fedyk, D., Shah, H., Bitar, N., and A. Takacs,
            "Generalized Multiprotocol Label Switching (GMPLS) Control
            of Ethernet Provider Backbone Traffic Engineering (PBB-
            TE)", RFC 6060, March 2011,
            <http://www.rfc-editor.org/info/rfc6060>.
 [RFC6370]  Bocci, M., Swallow, G., and E. Gray, "MPLS Transport
            Profile (MPLS-TP) Identifiers", RFC 6370, September 2011,
            <http://www.rfc-editor.org/info/rfc6370>.
 [RFC6374]  Frost, D. and S. Bryant, "Packet Loss and Delay
            Measurement for MPLS Networks", RFC 6374, September 2011,
            <http://www.rfc-editor.org/info/rfc6374>.

Bellagamba, et al. Standards Track [Page 29] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

 [RFC6427]  Swallow, G., Ed., Fulignoli, A., Ed., Vigoureux, M., Ed.,
            Boutros, S., and D. Ward, "MPLS Fault Management
            Operations, Administration, and Maintenance (OAM)", RFC
            6427, November 2011,
            <http://www.rfc-editor.org/info/rfc6427>.
 [RFC6428]  Allan, D., Ed., Swallow Ed., G., and J. Drake Ed.,
            "Proactive Connectivity Verification, Continuity Check,
            and Remote Defect Indication for the MPLS Transport
            Profile", RFC 6428, November 2011,
            <http://www.rfc-editor.org/info/rfc6428>.
 [RFC7260]  Takacs, A., Fedyk, D., and J. He, "GMPLS RSVP-TE
            Extensions for Operations, Administration, and Maintenance
            (OAM) Configuration", RFC 7260, June 2014,
            <http://www.rfc-editor.org/info/rfc7260>.

7.2. Informative References

 [LSP-PING-CONF]
            Bellagamba, E., Mirsky, G., Andersson, L., Skoldstrom, P.,
            Ward, D., and J. Drake, "Configuration of Proactive
            Operations, Administration, and Maintenance (OAM)
            Functions for MPLS-based Transport Networks using LSP
            Ping", Work in Progress, draft-ietf-mpls-lsp-ping-mpls-tp-
            oam-conf-09, January 2015.
 [RFC5462]  Andersson, L. and R. Asati, "Multiprotocol Label Switching
            (MPLS) Label Stack Entry: "EXP" Field Renamed to "Traffic
            Class" Field", RFC 5462, February 2009,
            <http://www.rfc-editor.org/info/rfc5462>.
 [RFC5920]  Fang, L., Ed., "Security Framework for MPLS and GMPLS
            Networks", RFC 5920, July 2010,
            <http://www.rfc-editor.org/info/rfc5920>.
 [RFC6371]  Busi, I., Ed. and D. Allan, Ed., "Operations,
            Administration, and Maintenance Framework for MPLS-Based
            Transport Networks", RFC 6371, September 2011,
            <http://www.rfc-editor.org/info/rfc6371>.
 [RFC6375]  Frost, D., Ed. and S. Bryant, Ed., "A Packet Loss and
            Delay Measurement Profile for MPLS-Based Transport
            Networks", RFC 6375, September 2011,
            <http://www.rfc-editor.org/info/rfc6375>.

Bellagamba, et al. Standards Track [Page 30] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

Acknowledgements

 The authors would like to thank David Allan, Lou Berger, Annamaria
 Fulignoli, Eric Gray, Andras Kern, David Jocha, and David Sinicrope
 for their useful comments.

Contributors

 This document is the result of a large team of authors and
 contributors.  The following is a list of the contributors:
 John Drake
 Benoit Tremblay

Bellagamba, et al. Standards Track [Page 31] RFC 7487 Extensions for MPLS-TP OAM Configuration March 2015

Authors' Addresses

 Elisa Bellagamba
 Ericsson
 EMail: elisa.bellagamba@ericsson.com
 Attila Takacs
 Ericsson
 EMail: attila.takacs@ericsson.com
 Gregory Mirsky
 Ericsson
 EMail: Gregory.Mirsky@ericsson.com
 Loa Andersson
 Huawei Technologies
 EMail: loa@mail01.huawei.com
 Pontus Skoldstrom
 Acreo AB
 Electrum 236
 Kista  164 40
 Sweden
 Phone: +46 70 7957731
 EMail: pontus.skoldstrom@acreo.se
 Dave Ward
 Cisco
 EMail: dward@cisco.com

Bellagamba, et al. Standards Track [Page 32]

/data/webs/external/dokuwiki/data/pages/rfc/rfc7487.txt · Last modified: 2015/03/13 20:05 by 127.0.0.1

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki