path: root/doc/rfc/rfc7487.txt

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.













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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.





































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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













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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



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   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



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   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)





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   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.











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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





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   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.





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    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.



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      *  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




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   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.






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   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







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      *  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].











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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".




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   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.








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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."







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   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.





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   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.






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   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.





















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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.




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   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.








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   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".




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   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.










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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






















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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





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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






























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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].





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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>.






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   [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>.






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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





































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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











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