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RFC 7369

Proposed STD
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GMPLS RSVP-TE Extensions for Ethernet Operations, Administration, and Maintenance (OAM) Configuration

 


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Internet Engineering Task Force (IETF)                         A. Takacs
Request for Comments: 7369                                       B. Gero
Category: Standards Track                                       Ericsson
ISSN: 2070-1721                                                  H. Long
                                                                  Huawei
                                                            October 2014


                 GMPLS RSVP-TE Extensions for Ethernet
    Operations, Administration, and Maintenance (OAM) Configuration

Abstract

   The work related to GMPLS Ethernet Label Switching (GELS) extended
   GMPLS RSVP-TE to support the establishment of Ethernet Label
   Switching Paths (LSPs).  IEEE Ethernet Connectivity Fault Management
   (CFM) specifies an adjunct Operations, Administration, and
   Maintenance (OAM) flow to check connectivity in Ethernet networks.
   CFM can also be used with Ethernet LSPs for fault detection and
   triggering recovery mechanisms.  The ITU-T Y.1731 specification
   builds on CFM and specifies additional OAM mechanisms, including
   Performance Monitoring, for Ethernet networks.  This document
   specifies extensions of the GMPLS RSVP-TE protocol to support the
   setup of the associated Ethernet OAM entities of Ethernet LSPs and
   defines the Ethernet technology-specific TLVs based on the GMPLS OAM
   Configuration Framework.  This document supports, but does not
   modify, the IEEE and ITU-T OAM mechanisms.

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/rfc7369.

Page 2 
Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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

Table of Contents

   1.  Background  . . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   2.  Overview of Ethernet OAM Operation  . . . . . . . . . . . . .   3
   3.  GMPLS RSVP-TE Extensions  . . . . . . . . . . . . . . . . . .   5
     3.1.  Operation Overview  . . . . . . . . . . . . . . . . . . .   5
     3.2.  OAM Configuration TLV . . . . . . . . . . . . . . . . . .   7
     3.3.  Ethernet OAM Configuration Sub-TLV  . . . . . . . . . . .   8
       3.3.1.  MD Name Sub-TLV . . . . . . . . . . . . . . . . . . .   9
       3.3.2.  Short MA Name Sub-TLV . . . . . . . . . . . . . . . .  10
       3.3.3.  MEP ID Sub-TLV  . . . . . . . . . . . . . . . . . . .  11
       3.3.4.  Continuity Check (CC) Sub-TLV . . . . . . . . . . . .  12
     3.4.  Proactive Performance Monitoring  . . . . . . . . . . . .  12
     3.5.  Summary of Ethernet OAM Configuration Errors  . . . . . .  13
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
     4.1.  RSVP-TE OAM Configuration Registry  . . . . . . . . . . .  14
     4.2.  Ethernet Sub-TLVs Sub-Registry  . . . . . . . . . . . . .  15
     4.3.  RSVP Error Code . . . . . . . . . . . . . . . . . . . . .  15
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  16
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  16
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .  16
     6.2.  Informative References  . . . . . . . . . . . . . . . . .  17
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  17
   Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . .  17
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  18

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1.  Background

   Provider Backbone Bridging - Traffic Engineering (PBB-TE)
   [IEEE.802.1Q-2011] decouples the Ethernet data and control planes and
   allows external control and management mechanisms to create
   explicitly routed Ethernet connections.  In addition, PBB-TE defines
   mechanisms for protection switching of bidirectional Ethernet
   connections.  Ethernet Connectivity Fault Management (CFM) defines an
   adjunct connectivity-monitoring OAM flow to check the liveliness of
   Ethernet networks [IEEE.802.1Q-2011], including the monitoring of
   specific explicitly routed Ethernet connections.  The ITU-T
   Recommendation Y.1731 [ITU-T.G.8013-2013] extended CFM and specified
   additional OAM functionality.

   In the IETF, the work related to GMPLS Ethernet Label Switching
   (GELS) extended the GMPLS control plane to support the establishment
   of explicitly routed Ethernet connections [RFC5828] [RFC6060].  We
   refer to GMPLS-established Ethernet connections as "Ethernet LSPs".
   GELS enables the application of MPLS-TE and GMPLS provisioning and
   recovery features in Ethernet networks.

   The use of GMPLS RSVP-TE to support the establishment and
   configuration of OAM entities with LSP signaling is defined in a
   technology-agnostic way in [RFC7260].  The purpose of this document
   is to specify the additional technology-specific OAM entities to
   support Ethernet connections.

1.1.  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 [RFC2119].

2.  Overview of Ethernet OAM Operation

   For the purposes of this document, we only discuss Ethernet OAM
   aspects that are relevant for proactive connectivity monitoring of
   Ethernet LSPs and assume that on-demand OAM functions will be
   supported by management-plane operations.

   PBB-TE defines point-to-point Ethernet Switched Paths (ESPs) as a
   provisioned, traffic-engineered, unidirectional connectivity,
   identified by the 3-tuple [ESP-MAC DA, ESP-MAC SA, ESP-VID], where
   the ESP-MAC DA is the destination address of the ESP, the ESP-MAC SA
   is the source address of the ESP, and the ESP-VID is a VLAN
   identifier allocated for explicitly routed connections.  To form a
   bidirectional PBB-TE connection, two co-routed point-to-point ESPs
   are combined.  The combined ESPs must have the same ESP-MAC addresses

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   but may have different ESP-VIDs.  The formed co-routed bidirectional
   path is a path where the forward and backward directions follow the
   same route (links and nodes) across the network.

   Note that although it would be possible to use GMPLS to set up a
   single unidirectional ESP, the Ethernet OAM mechanisms are only fully
   functional when bidirectional connections are established with co-
   routed ESPs.  Therefore, the scope of this document only covers
   bidirectional point-to-point PBB-TE connections.

   At both ends of the bidirectional point-to-point PBB-TE connection,
   one Maintenance Entity Group End Point (MEP) is configured.  The MEPs
   monitoring a PBB-TE connection must be configured with the same
   Maintenance Domain Level (MD Level) and Maintenance Association
   Identifier (MAID).  Each MEP has a unique identifier, the MEP ID.
   Besides these identifiers, a MEP monitoring a PBB-TE connection must
   be provisioned with the 3-tuples [ESP-MAC DA, ESP-MAC SA, ESP-VID] of
   the two ESPs.

   In the case of point-to-point VLAN connections, the connection may be
   identified with a single VLAN or with two VLANs, one for each
   direction.  Therefore, instead of the 3-tuples of the PBB-TE ESPs,
   MEPs must be provisioned with the proper VLAN identifiers.

   MEPs exchange Connectivity Check Messages (CCMs) periodically with
   fixed intervals.  Eight distinct intervals are defined in
   [IEEE.802.1Q-2011]:

                +---+--------------------+----------------+
                | # | CCM Interval (CCI) | 3-Bit Encoding |
                +---+--------------------+----------------+
                | 0 |      Reserved      |      000       |
                |   |                    |                |
                | 1 |      3 1/3 ms      |      001       |
                |   |                    |                |
                | 2 |       10 ms        |      010       |
                |   |                    |                |
                | 3 |       100 ms       |      011       |
                |   |                    |                |
                | 4 |        1 s         |      100       |
                |   |                    |                |
                | 5 |        10 s        |      101       |
                |   |                    |                |
                | 6 |       1 min        |      110       |
                |   |                    |                |
                | 7 |       10 min       |      111       |
                +---+--------------------+----------------+
                      Table 1: CCM Interval Encoding

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   If three consecutive CCMs are lost, connectivity failure is declared.
   The MEP detecting the failure will signal the defect to the remote
   MEP in the subsequent CCMs it emits by setting the Remote Defect
   Indicator (RDI) bit in the CCM.  If a MEP receives a CCM with the RDI
   bit set, it immediately declares failure.  The detection of a failure
   may trigger protection switching mechanisms or may be signaled to a
   management system.

   At each transit node, Maintenance Entity Group Intermediate Points
   (MIPs) may be established to help failure localization, e.g., using
   link trace and loopback functions.  MIPs need to be provisioned with
   a subset of the MEP identification parameters described above.

3.  GMPLS RSVP-TE Extensions

3.1.  Operation Overview

   To simplify the configuration of connectivity monitoring, the
   associated MEPs should be automatically established when an Ethernet
   LSP is signaled.  To monitor an Ethernet LSP, a set of parameters
   must be provided to set up a Maintenance Association and related
   MEPs.  Optionally, MIPs may be created at the transit nodes of the
   Ethernet LSP.  The LSP Attribute Flags "OAM MEP entities desired" and
   "OAM MIP entities desired", as described in [RFC7260], are used to
   signal that the respective OAM entities must be established.  An OAM
   Configuration TLV, as described in [RFC7260], is added to the
   LSP_ATTRIBUTES or LSP_REQUIRED_ATTRIBUTES objects specifying that
   Ethernet OAM is to be set up for the LSP.  Information specific to
   Ethernet OAM, as described below, is carried in the new Ethernet OAM
   Configuration Sub-TLV (see Section 3.3) within the OAM Configuration
   TLV.

   o  A unique MAID must be allocated for the PBB-TE connection, and
      both MEPs must be configured with the same information.  The MAID
      consists of an optional Maintenance Domain Name (MD Name) and a
      mandatory Short Maintenance Association Name (Short MA Name).
      Various formatting rules for these names have been defined in
      [IEEE.802.1Q-2011].  Since this information is also carried in all
      CCMs, the combined length of the MD Name and Short MA Name is
      limited to 44 bytes (see [IEEE.802.1Q-2011] for the details of the
      message format).  How these parameters are determined is out of
      the scope of this document.

   o  Each MEP must be provisioned with a MEP ID.  The MEP ID uniquely
      identifies a given MEP within a Maintenance Association.  That is,
      the combination of MAID and MEP ID must uniquely identify a MEP.
      How the value of the MEP ID is determined is out of the scope of
      this document.

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   o  The Maintenance Domain Level (MD Level) allows hierarchical
      separation of monitoring entities.  [IEEE.802.1Q-2011] allows
      differentiation of eight levels.  How the value of the MD Level is
      determined is out of the scope of this document.  Note that
      probably for all Ethernet LSPs, a single (default) MD Level will
      be used within a network domain.

   o  The desired CCM Interval must be specified by the management
      system based on service requirements or operator policy.  The same
      CCM Interval must be set in each of the MEPs monitoring a given
      Ethernet LSP.  How the value of the CCM Interval is determined is
      out of the scope of this document.

   o  The desired forwarding priority to be set by MEPs for the CCM
      frames may be specified.  The same CCM priority must be set in
      each of the MEPs monitoring a given Ethernet LSP.  How CCM
      priority is determined is out of the scope of this document.  Note
      that the highest priority should be used as the default CCM
      priority.

   o  MEPs must be aware of their own reachability parameters and those
      of the remote MEP.  In the case of bidirectional point-to-point
      PBB-TE connections, this requires that the 3-tuples [ESP-MAC A,
      ESP-MAC B, ESP-VID1] and [ESP-MAC B, ESP-MAC A, ESP-VID2] are
      configured in each MEP, where the ESP-MAC A is the same as the
      local MEP's Media Access Control (MAC) address and ESP-MAC B is
      the same as the remote MEP's MAC address.  The GMPLS Ethernet
      Label format, as defined in [RFC6060], consists of the ESP-MAC DA
      and ESP-VID.  Hence, the necessary reachability parameters for the
      MEPs can be obtained from the Ethernet Labels (i.e., carried in
      the downstream and upstream labels).  In the case of point-to-
      point VLAN connections, MEPs need to be provisioned with the VLAN
      identifiers only, which can be derived similarly from the Ethernet
      Labels.

   Based on the procedures described in [RFC6060] for bidirectional PBB-
   TE Ethernet LSP establishment, the Ethernet OAM configuration
   procedures are as follows.

   When the RSVP-TE signaling is initiated for the bidirectional
   Ethernet LSP, the local node generates a Path message and:

   o  Allocates an upstream label formed by combining its MAC address
      (ESP-MAC A) and locally selected VID (ESP-VID1), which will be
      used to receive traffic;

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   o  MUST include the OAM Configuration TLV with OAM Type set to
      Ethernet OAM in the LSP_ATTRIBUTES or LSP_REQUIRED_ATTRIBUTES
      objects;

   o  MUST include the OAM Function Flags Sub-TLV in the OAM
      Configuration TLV and set the OAM function flags as needed;

   o  MUST include an Ethernet OAM Configuration Sub-TLV in the OAM
      Configuration TLV that specifies the CCM Interval and MD Level;

   o  MAY add an MD Name Sub-TLV (optional) and MUST add a Short MA Name
      Sub-TLV (required) to the Ethernet OAM Configuration Sub-TLV,
      which will unambiguously identify a Maintenance Association for
      this specific PBB-TE connection.  Note that values for these
      parameters may be derived from the GMPLS LSP identification
      parameters; and

   o  MUST include a MEP ID Sub-TLV in the Ethernet OAM Configuration
      Sub-TLV and select two distinct integer values to identify the
      local and remote MEPs within the Maintenance Association created
      for monitoring of the point-to-point PBB-TE connection.

   Once the remote node receives the Path message, it can use the
   UPSTREAM_LABEL to extract the reachability information of the
   initiator.  Then, it allocates a Label by selecting a local MAC
   address (ESP-MAC B) and VID (ESP-VID2) that will be used to receive
   traffic.  These parameters determine the reachability information of
   the local MEP.  That is, the 3-tuples [ESP-MAC A, ESP-MAC B, ESP-
   VID1] and [ESP-MAC B, ESP-MAC A, ESP-VID2] are derived from the
   Ethernet Labels.  In addition, the information received in the
   Ethernet OAM Configuration TLV is used to configure the local MEP.

   Once the Resv message successfully arrives to the initiator, this end
   can extract the remote side's reachability information from the Label
   object and therefore has all the information needed to properly
   configure its local MEP.

3.2.  OAM Configuration TLV

   This TLV is specified in [RFC7260] and is used to select which OAM
   technology/method should be used for the LSP.  In this document, a
   new OAM Type, Ethernet OAM, is defined.  IANA has allocated OAM Type
   1 for Ethernet OAM in the "RSVP-TE OAM Configuration Registry".

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     RSVP-TE OAM Configuration Registry

       OAM Type           Description
     ------------      ------------------
         1               Ethernet OAM

   When the Ethernet OAM Type is requested, the receiving node should
   look for the corresponding technology-specific Ethernet OAM
   Configuration Sub-TLV.

3.3.  Ethernet OAM Configuration Sub-TLV

   The Ethernet OAM Configuration Sub-TLV (depicted below) is defined
   for configuration parameters specific to Ethernet OAM.  The Ethernet
   OAM Configuration Sub-TLV, when used, MUST be carried in the OAM
   Configuration TLV.  This new sub-TLV accommodates Ethernet 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           Type 32             |           Length              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Version |MD L.|           Reserved (set to all 0s)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                           Sub-TLVs                            ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: Indicates a new type, the Ethernet OAM Configuration Sub-TLV.
   IANA has assigned the value 32 from the "OAM Sub-TLVs" space in the
   "RSVP-TE OAM Configuration Registry".

   Length: Indicates the total length of the TLV including padding and
   including the Type and Length fields.

   Version: Identifies the CFM protocol version according to
   [IEEE.802.1Q-2011].  If a node does not support a specific CFM
   version, an error MUST be generated: "OAM Problem/Unsupported OAM
   Version".

   MD L. (MD Level): Indicates the desired MD Level.  Possible values
   are defined according to [IEEE.802.1Q-2011].  If a node does not
   support a specific MD Level, an error MUST be generated: "OAM
   Problem/Unsupported MD Level".

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3.3.1.  MD Name Sub-TLV

   The optional MD Name Sub-TLV is depicted below.  It MAY be used for
   MD naming.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           Type (1)            |           Length              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Format     |  Name Length  |   Reserved (set to all 0s)    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                            MD Name                            ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: 1, MD Name Sub-TLV.  IANA will maintain an Ethernet TLV Type
   space in the "RSVP-TE OAM Configuration Registry" for the sub-TLV
   types carried in the Ethernet OAM Configuration Sub-TLV.

   Length: Indicates the total length of the TLV, including padding and
   the Type and Length fields.

   Format: According to [IEEE.802.1Q-2011].

   Name Length: The length of the MD Name field in bytes.  This is
   necessary to allow non-4-byte padded MD Name lengths.

   MD Name: Variable-length field, formatted according to the format
   specified in the Format field.

   If an undefined Format is specified, an error MUST be generated: "OAM
   Problem/Unknown MD Name Format".  Also, the combined length of MD
   Name and Short MA Name MUST be less than or equal to 44 bytes.  If
   this is violated, an error MUST be generated: "OAM Problem/Name
   Length Problem".  Note that it is allowed to have no MD Name;
   therefore, the MD Name Sub-TLV is optional.  In this case, the MA
   Name must uniquely identify a Maintenance Association.

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3.3.2.  Short MA Name Sub-TLV

   The Short MA Name Sub-TLV is depicted below.  This sub-TLV MUST be
   present in the Ethernet 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           Type (2)            |           Length              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Format     |  Name Length  |   Reserved (set to all 0s)    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                       Short MA Name                           ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: 2, Short MA Name Sub-TLV.  IANA will maintain an Ethernet TLV
   Type space in the "RSVP-TE OAM Configuration Registry" for the sub-
   TLV types carried in the Ethernet OAM Configuration Sub-TLV.

   Length: Indicates the total length of the TLV, including padding and
   the Type and Length fields.

   Format: According to [IEEE.802.1Q-2011].

   Name Length: The length of the Short MA Name field in bytes.  This is
   necessary to allow non-4-byte padded MA Name lengths.

   Short MA Name: Variable-length field formatted according to the
   format specified in the Format field.

   If an undefined Format is specified, an error MUST be generated: "OAM
   Problem/Unknown MA Name Format".  Also, the combined length of MD
   Name and Short MA Name MUST be less than or equal to 44 bytes.  If
   this is violated, an error MUST be generated: "OAM Problem/Name
   Length Problem".  Note that it is allowed to have no MD Name; in this
   case, the MA Name MUST uniquely identify a Maintenance Association.

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3.3.3.  MEP ID Sub-TLV

   The MEP ID Sub-TLV is depicted below.  This sub-TLV MUST be present
   in the Ethernet 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           Type (3)            |           Length              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |        Local MEP ID           |T|R|      Reserved             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |        Remote MEP ID          |T|R|      Reserved             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: 3, MEP ID Sub-TLV.  IANA will maintain an Ethernet TLV Type
   space in the "RSVP-TE OAM Configuration Registry" for the sub-TLV
   types carried in the Ethernet OAM Configuration Sub-TLV.

   Length: Indicates the total length of the TLV, including padding and
   the Type and Length fields.

   Local MEP ID: A 16-bit integer value in the range 1-8191 of the MEP
   ID on the initiator side.

   Remote MEP ID: A 16-bit integer value in the range 1-8191 of the MEP
   ID to be set for the MEP established at the receiving side.  This
   value is determined by the initiator node.  This is possible since a
   new MAID is assigned to each PBB-TE connection, and MEP IDs must be
   only unique within the scope of the MAID.

   Two flags are defined: Transmit (T) and Receive (R).  When T is set,
   the corresponding MEP MUST send OAM packets.  When R is set, the
   corresponding MEP MUST expect to receive OAM packets.  These flags
   are used to configure the role of MEPs.

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3.3.4.  Continuity Check (CC) Sub-TLV

   The Continuity Check (CC) Sub-TLV is depicted below.  This sub-TLV
   MUST be present in the Ethernet 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           Type (4)            |           Length              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Prio  | CCM I |           Reserved (set to all 0s)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: 4, Continuity Check (CC) Sub-TLV.  IANA will maintain an
   Ethernet TLV Type space in the "RSVP-TE OAM Configuration Registry"
   for the sub-TLV types carried in the Ethernet OAM Configuration Sub-
   TLV.

   Length: Indicates the total length of the TLV, including padding and
   the Type and Length fields.

   Prio: Indicates the priority to be set for CCM frames.  In Ethernet,
   3 bits carried in VLAN TAGs identify priority information.  Setting
   the priority is optional.  If the most significant bit is set to
   zero, the subsequent 3 priority bits will be ignored, and priority
   bits of the Ethernet CCM frame will be set based on default values
   specified in the Ethernet nodes.  If the most significant bit is set
   to 1, the subsequent 3 bits will be used to set the priority bits of
   the Ethernet CCM frame.

   CCM I (CCM Interval): MUST be set according to the 3-bit encoding
   [IEEE.802.1Q-2011] shown in Table 1.  As a consequence, the most
   significant bit will be set to 0.  Four bits are allocated to support
   the configuration of CCM Intervals that may be specified in the
   future.  If a node does not support the requested CCM Interval, an
   error MUST be generated: "OAM Problem/Unsupported CC Interval".

3.4.  Proactive Performance Monitoring

   Ethernet OAM functions for Performance Monitoring (PM) allow
   measurements of different performance parameters including Frame Loss
   Ratio, Frame Delay, and Frame Delay Variation as defined in
   [ITU-T.G.8013-2013].  Only a subset of PM functions are operated in a
   proactive fashion to monitor the performance of the connection
   continuously.  Proactive PM supports Fault Management functions by
   providing an indication of decreased service performance and
   therefore may provide triggers to initiate recovery procedures.

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   While on-demand PM functions are, for the purposes of this document,
   always initiated by management commands, for proactive PM, it may be
   desirable to utilize the control plane for configuration and
   activation together with Fault Management functions such as the
   Continuity Check.

   [ITU-T.G.8013-2013] defines dual-ended Loss Measurement as proactive
   OAM for Performance Monitoring and as a PM function applicable to
   Fault Management.  For dual-ended Loss Measurement, each MEP
   piggybacks transmitted and received frame counters on CC messages to
   support and synchronize bidirectional Loss Measurements at the MEPs.
   Dual-ended Loss Measurement is supported by setting the Performance
   Monitoring/Loss OAM Function Flag and the Continuity Check Flag in
   the OAM Function Flags Sub-TLV [RFC7260] and configuring the
   Continuity Check functionality by including the Ethernet OAM
   Configuration Sub-TLV.  No additional configuration is required for
   this type of Loss Measurement.

3.5.  Summary of Ethernet OAM Configuration Errors

   In addition to the error values specified in [RFC7260], this document
   defines the following values for the "OAM Problem" Error Code.

   o  If a node does not support a specific CFM version, an error MUST
      be generated: "OAM Problem/Unsupported OAM Version".

   o  If a node does not support a specific MD Level, an error MUST be
      generated: "OAM Problem/Unsupported MD Level".

   o  If an undefined MD name format is specified, an error MUST be
      generated: "OAM Problem/Unknown MD Name Format".

   o  If an undefined MA name format is specified, an error MUST be
      generated: "OAM Problem/Unknown MA Name Format".

   o  The combined length of MD Name and Short MA Name must be less than
      or equal to 44 bytes.  If this is violated, an error MUST be
      generated: "OAM Problem/Name Length Problem".

   o  If a node does not support the requested CCM Interval, an error
      MUST be generated: "OAM Problem/Unsupported CC Interval".

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4.  IANA Considerations

4.1.  RSVP-TE OAM Configuration Registry

   IANA maintains the "RSVP-TE OAM Configuration Registry".  IANA has
   assigned an "OAM Type" from this registry as follows:

   o  "Ethernet OAM" has been allocated type 1 from the "OAM Types" sub-
      registry of the "RSVP-TE OAM Configuration Registry".

   o  "Ethernet OAM Configuration Sub-TLV" has been allocated type 32
      from the technology-specific range of the "OAM Sub-TLVs" sub-
      registry of the "RSVP-TE OAM Configuration Registry".

   RSVP-TE OAM Configuration Registry

     OAM Types

     OAM Type Number | Description  | Reference
     -------------------------------------------
           1         | Ethernet OAM | [RFC7369]


     OAM Sub-TLVs

     Sub-TLV Type |        Description               |   Ref.
     -----------------------------------------------------------
         32       |Ethernet OAM Configuration Sub-TLV| [RFC7369]

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4.2.  Ethernet Sub-TLVs Sub-Registry

   IANA will maintain an "Ethernet Sub-TLVs Sub-Registry" in the "RSVP-
   TE OAM Configuration Registry" for the sub-TLV types carried in the
   Ethernet OAM Configuration Sub-TLV.  This document defines the
   following types.

   Ethernet Sub-TLVs Sub-Registry

      Range       |  Registration Procedures
      ------------+--------------------------
      0-65534     |  IETF Review
       65535      |  Experimental

     Sub-TLV Type |      Description               |  Ref.
     ---------------------------------------------------------
         0        |  Reserved                      | [RFC7369]
         1        |  MD Name Sub-TLV               | [RFC7369]
         2        |  Short MA Name Sub-TLV         | [RFC7369]
         3        |  MEP ID Sub-TLV                | [RFC7369]
         4        |  Continuity Check Sub-TLV      | [RFC7369]
         5-65534  |  Unassigned                    | [RFC7369]
         65535    |  Reserved for Experimental Use | [RFC7369]

4.3.  RSVP Error Code

   IANA maintains an Error Code, "OAM Problem", in the "Error Codes and
   Globally-Defined Error Value Sub-Codes" sub-registry of the "Resource
   Reservation Protocol (RSVP) Parameters" registry.  [RFC7260] defines
   a set of Error Value sub-codes for the "OAM Problem" Error Code.
   This document defines additional Error Value sub-codes for the "OAM
   Problem" Error Code as summarized below.

          Value | Description               | Reference
         -------+---------------------------+-----------
             7  | Unsupported OAM Version   | [RFC7369]
             8  | Unsupported MD Level      | [RFC7369]
             9  | Unknown MD Name Format    | [RFC7369]
            10  | Unknown MA Name Format    | [RFC7369]
            11  | Name Length Problem       | [RFC7369]
            12  | Unsupported CC Interval   | [RFC7369]

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5.  Security Considerations

   This document does not introduce any additional security issues to
   those discussed in [RFC7260] and [RFC6060].

   The signaling of OAM-related parameters and the automatic
   establishment of OAM entities based on RSVP-TE messages add a new
   aspect to the security considerations discussed in [RFC3473].  In
   particular, a network element could be overloaded if a remote
   attacker targeted that element by sending frequent periodic messages
   requesting liveliness monitoring of a high number of LSPs.  Such an
   attack can efficiently be prevented when mechanisms for message
   integrity and node authentication are deployed.  Since the OAM
   configuration extensions rely on the hop-by-hop exchange of exiting
   RSVP-TE messages, procedures specified for RSVP message security in
   [RFC2747] can be used to mitigate possible attacks.

   For a more comprehensive discussion of GMPLS security and attack
   mitigation techniques, please see "Security Framework for MPLS and
   GMPLS Networks" [RFC5920].

6.  References

6.1.  Normative References

   [IEEE.802.1Q-2011]
              IEEE, "IEEE Standard for Local and metropolitan area
              networks--Media Access Control (MAC) Bridges and Virtual
              Bridged Local Area Networks", IEEE Std 802.1Q, 2011.

   [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>.

   [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>.

   [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>.

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6.2.  Informative References

   [ITU-T.G.8013-2013]
              International Telecommunications Union, "OAM functions and
              mechanisms for Ethernet based networks", ITU-T
              Recommendation G.8013/Y.1731, November 2011.

   [RFC2747]  Baker, F., Lindell, B., and M. Talwar, "RSVP Cryptographic
              Authentication", RFC 2747, January 2000,
              <http://www.rfc-editor.org/info/rfc2747>.

   [RFC3473]  Berger, L., "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>.

   [RFC5828]  Fedyk, D., Berger, L., and L. Andersson, "Generalized
              Multiprotocol Label Switching (GMPLS) Ethernet Label
              Switching Architecture and Framework", RFC 5828, March
              2010, <http://www.rfc-editor.org/info/rfc5828>.

   [RFC5920]  Fang, L., "Security Framework for MPLS and GMPLS
              Networks", RFC 5920, July 2010,
              <http://www.rfc-editor.org/info/rfc5920>.

Acknowledgements

   The authors would like to thank Francesco Fondelli, Adrian Farrel,
   Loa Andersson, Eric Gray, and Dimitri Papadimitriou for their useful
   comments.

Contributors

   Don Fedyk
   EMail: don.fedyk@hp.com

   Dinesh Mohan
   EMail: dinmohan@hotmail.com

Top      ToC       Page 18 
Authors' Addresses

   Attila Takacs
   Ericsson
   Konyves Kalman krt. 11.
   Budapest  1097
   Hungary

   EMail: attila.takacs@ericsson.com


   Balazs Peter Gero
   Ericsson
   Konyves Kalman krt. 11.
   Budapest  1097
   Hungary

   EMail: balazs.peter.gero@ericsson.com


   Hao Long
   Huawei
   China

   EMail: lonho@huawei.com