RSVP-TE Summary Fast Reroute Extensions for LSP Tunnels
draft-ietf-mpls-summary-frr-rsvpte-03

MPLS Working Group                                            M. Taillon
Internet-Draft                                       Cisco Systems, Inc.
Intended status: Standards Track                            T. Saad, Ed.
Expires: November 3, 2019                               Juniper Networks
                                                               R. Gandhi
                                                     Cisco Systems, Inc.
                                                             A. Deshmukh
                                                        Juniper Networks
                                                                 M. Jork
                                                          128 Technology
                                                               V. Beeram
                                                        Juniper Networks
                                                            May 02, 2019

        RSVP-TE Summary Fast Reroute Extensions for LSP Tunnels
                 draft-ietf-mpls-summary-frr-rsvpte-03

Abstract

   This document defines Resource Reservation Protocol (RSVP) Traffic-
   Engineering (TE) signaling extensions that reduce the amount of RSVP
   signaling required for Fast Reroute (FRR) procedures and subsequently
   improve the scalability of the RSVP-TE signaling when undergoing FRR
   convergence after a link or node failure.  Such extensions allow the
   RSVP message exchange between the Point of Local Repair (PLR) and the
   Merge Point (MP) to be independent of the number of protected Label
   Switched Paths (LSPs) traversing between them when facility bypass
   FRR protection is used.  The signaling extensions are fully backwards
   compatible with nodes that do not support them.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on November 3, 2019.

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Copyright Notice

   Copyright (c) 2019 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
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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Conventions Used in This Document . . . . . . . . . . . . . .   4
     2.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
     2.2.  Acronyms and Abbreviations  . . . . . . . . . . . . . . .   4
   3.  Extensions for Summary FRR Signaling  . . . . . . . . . . . .   4
     3.1.  B-SFRR-Ready Extended ASSOCIATION Object  . . . . . . . .   5
       3.1.1.  IPv4 B-SFRR-Ready IPv4 Extended ASSOCIATION ID  . . .   6
       3.1.2.  IPv6 B-SFRR-Ready IPv6 Extended ASSOCIATION ID  . . .   7
     3.2.  B-SFRR-Active Extended ASSOCIATION Object . . . . . . . .  10
       3.2.1.  B-SFRR-Active Extended ASSOCIATION ID . . . . . . . .  11
     3.3.  Signaling Procedures Prior to Failure . . . . . . . . . .  12
       3.3.1.  PLR Signaling Procedure . . . . . . . . . . . . . . .  12
       3.3.2.  MP Signaling Procedure  . . . . . . . . . . . . . . .  12
     3.4.  Signaling Procedures Post Failure . . . . . . . . . . . .  13
       3.4.1.  PLR Signaling Procedure . . . . . . . . . . . . . . .  13
       3.4.2.  MP Signaling Procedure  . . . . . . . . . . . . . . .  14
     3.5.  Refreshing Summary FRR Active LSPs  . . . . . . . . . . .  15
   4.  Compatibility . . . . . . . . . . . . . . . . . . . . . . . .  15
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  15
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  15
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  16
   8.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  16
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  16
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  16
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  17
     9.3.  URIs  . . . . . . . . . . . . . . . . . . . . . . . . . .  17
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  17

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1.  Introduction

   The Fast Reroute (FRR) procedures defined in [RFC4090] describe the
   mechanisms for the Point of Local Repair (PLR) to reroute traffic and
   signaling of a protected RSVP-TE LSP onto the bypass tunnel in the
   event of a TE link or node failure.  Such signaling procedures are
   performed individually for each affected protected LSP.  This may
   eventually lead to control plane scalability and latency issues on
   the PLR and/or the MP due to limited memory and CPU processing
   resources.  This condition is exacerbated when the failure affects
   large number of protected LSPs that traverse the same PLR and Merge
   Point (MP) nodes.

   For example, in a large scale RSVP-TE LSPs deployment, a single LSR
   acting as a PLR node may host tens of thousands of protected RSVP-TE
   LSPs egressing the same link, and also act as a MP node for similar
   number of LSPs ingressing the same link.  In the event of the failure
   of the link or neighbor node, the RSVP-TE control plane of the node
   when acting as PLR becomes busy rerouting protected LSPs signaling
   over the bypass tunnel(s) in one direction, and when acting as an MP
   node becomes busy merging RSVP states from signaling received over
   bypass tunnels for LSP(s) in the reverse direction.  Subsequently,
   the head-end LER(s) that are notified of the local repair at
   downstream LSR will attempt to (re)converge affected RSVP- TE LSPs
   onto newly computed paths - possibly traversing the same previously
   affected LSR(s).  As a result, the RSVP-TE control plane at the PLR
   and MP becomes overwhelmed by the amount of FRR RSVP-TE processing
   overhead following the link or node failure, and the competing other
   control plane protocol(s) (e.g. the IGP) that undergo their
   convergence at the same time.

   The extensions defined in this document enable a MP node to become
   aware of the PLR node's bypass tunnel assignment group and allow FRR
   procedures between PLR node and MP node to be signaled and processed
   on groups of LSPs.

   As defined in [RFC2961], Summary Refresh procedures use MESSAGE_ID to
   refresh the RSVP Path and Resv states to help with the scale.  The
   MESSAGE_ID information for the rerouted PATH and RESV states are
   exchanged between PLR and MP nodes between PLR and MP nodes a priori
   to the fault such that Summary Refresh procedures defined in
   [RFC2961] can continue to be used to refresh the rerouted state(s)
   after FRR has occurred.

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2.  Conventions Used in This Document

2.1.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in BCP 14, RFC 2119
   [RFC2119].

2.2.  Acronyms and Abbreviations

   The reader is assumed to be familiar with terms and abbreviations
   used in [RFC3209] and [RFC4090].

   The following abbreviations are also used in this document:

      LSR: Label Switching Router

      LER: Label Edge Router

      MPLS: Multiprotocol Label Switching

      LSP: Label Switched Path

      MP: Merge Point node as defined in [RFC4090]

      PLR: Point of Local Repair node as defined in [RFC4090]

      FRR: Fast Reroute as defined in [RFC4090]

      B-SFRR-Ready: Bypass Summary FRR Ready Extended ASSOCIATION
      object.  Added by the PLR for each LSP protected by the bypass
      tunnel.

      B-SFRR-Active: Bypass Summary FRR Active Extended ASSOCIATION
      object.  Used to notify the MP node of one ore more groups of
      protected LSP(s) that are being protected by the specified bypass
      tunnel are being rerouted.

3.  Extensions for Summary FRR Signaling

   The RSVP ASSOCIATION object is defined in [RFC4872] as a means to
   associate LSPs with each other.  For example, in the context of
   GMPLS-controlled LSP(s), the object is used to associate recovery
   LSPs with the LSP they are protecting.  The Extended ASSOCIATION
   object is introduced in [RFC6780] to expand on the possible usage of
   the ASSOCIATION object and generalize the definition of the Extended
   Association ID field.

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   This document proposes the use of the Extended ASSOCIATION object to
   carry the Summary FRR information and associate the protected LSP(s)
   with the bypass tunnel that protects them.  Two new Association Types
   for the Extended ASSOCIATION object, and new Extended Association IDs
   are proposed in this draft to describe the Bypass Summary FRR Ready
   (B-SFRR-Ready) and the Bypass Summary FRR Active (B-SFRR-Active)
   associations.

   The PLR creates and manages the Summary FRR LSP groups
   (Bypass_Group_Identifiers) and shares them with the MP via signaling.
   Protected LSPs sharing the same egress link and bypass assignment are
   grouped together and are assigned the same group.  The MP maintains
   the PLR group assignments learned via signaling, and acknowledges the
   group assignments via signaling.  Once the PLR receives the
   acknowledgment, FRR signaling can proceed as group based.

   The PLR node that supports Summary FRR procedures adds the Extended
   ASSOCIATION object with Type B-SFRR-Ready and respective Extended
   Association ID in the RSVP Path message of the protected LSP to
   inform the MP of the PLR's assigned bypass tunnel, Summary FRR
   Bypass_Group_Identifier, and the MESSAGE_ID that the PLR will use to
   refresh the protected LSP PATH state after FRR occurs.

   The MP node that supports Summary FRR procedures adds the B-SFRR-
   Ready Extended ASSOCIATION object and respective Extended Association
   ID in the RSVP Resv message of the protected LSP to acknowledge the
   PLR's bypass tunnel assignment, and provide the MESSAGE_ID object
   that the MP node will use to refresh the protected LSP RESV state
   after FRR occurs.

   This document also defines a new Association Type for the Extended
   ASSOCIATION object and new Extended Association ID to describe the B-
   SFRR-Active association.  The B-SFRR-Active Extended ASSOCIATION
   object and Extended Association ID are sent by PLR after activating
   FRR procedures on the PLR.  The B-SFRR-Active Extended ASSOCIATION
   object and Extended Association ID are sent within the RSVP Path
   message of the bypass LSP to inform the MP node that one or more
   groups of protected LSPs protected by the bypass tunnel are now being
   rerouted over the bypass tunnel.

3.1.  B-SFRR-Ready Extended ASSOCIATION Object

   The Extended ASSOCIATION object is populated using the rules defined
   below to associate a protected LSP with the bypass LSP that is
   protecting it when Summary FRR procedures are enabled.

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   The Association Type, Association ID, and Association Source MUST be
   set as defined in [RFC4872] for the ASSOCIATION Object.  More
   specifically:

   Association Source:

     The Association Source is set to an address of the PLR node.

   Association Type:

     A new Association Type is defined for B-SFRR-Ready as follows:

     Value      Type
     -------    ------
     (TBD-1)    Bypass Summary FRR Ready Association (B-SFRR-Ready)

   Extended ASSOCIATION ID for B-SFRR-Ready:

     The B-SFRR-Ready Extended ASSOCIATION ID is
     populated by the PLR for the Bypass Summary FRR Ready association.
     The rules to populate the Extended ASSOCIATION ID in this case are
     described below.

3.1.1.  IPv4 B-SFRR-Ready IPv4 Extended ASSOCIATION ID

   The IPv4 Extended ASSOCIATION ID for the B-SFRR-Ready association
   type has the following format:

        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |         Bypass_Tunnel_ID      |           Reserved            |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                Bypass_Source_IPv4_Address                     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                Bypass_Destination_IPv4_Address                |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                Bypass_Group_Identifier                        |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                MESSAGE_ID                                     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

        Figure 1: The IPv4 Extended ASSOCIATION ID for B-SFRR-Ready

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     Bypass_Tunnel_ID: 16 bits

           The bypass tunnel identifier.

     Reserved: 16 bits

           Reserved for future use.

     Bypass_Source_IPv4_Address: 32 bits

           The bypass tunnel source IPV4 address.

     Bypass_Destination_IPv4_Address: 32 bits

           The bypass tunnel destination IPV4 address.

     Bypass_Group_Identifier: 32 bits

           The bypass tunnel group identifier.

     MESSAGE_ID

           A MESSAGE_ID object as defined by [RFC2961].

3.1.2.  IPv6 B-SFRR-Ready IPv6 Extended ASSOCIATION ID

   The IPv6 Extended ASSOCIATION ID field for the B-SFRR-Ready
   association type has the following format:

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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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |         Bypass_Tunnel_ID      |           Reserved            |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                                                               |
       +                                                               +
       |                                                               |
       +                Bypass_Source_IPv6_Address                     +
       |                                                               |
       +                                                               +
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                                                               |
       +                                                               +
       |                                                               |
       +                Bypass_Destination_IPv6_Address                +
       |                                                               |
       +                                                               +
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                Bypass_Group_Identifier                        |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                MESSAGE_ID                                     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

        Figure 2: The IPv6 Extended ASSOCIATION ID for B-SFRR-Ready

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     Bypass_Tunnel_ID: 16 bits

           The bypass tunnel identifier.

     Reserved: 16 bits

           Reserved for future use.

     Bypass_Source_IPv6_Address: 128 bits

           The bypass tunnel source IPV6 address.

     Bypass_Destination_IPv6_Address: 128 bits

           The bypass tunnel destination IPV6 address.

     Bypass_Group_Identifier: 32 bits

           The bypass tunnel group identifier.

     MESSAGE_ID

           A MESSAGE_ID object as defined by [RFC2961].

   The PLR assigns a bypass tunnel and Bypass_Group_Identifier for each
   protected LSP.  The same Bypass_Group_Identifier is used for the set
   of protected LSPs that share the same bypass tunnel and traverse the
   same egress link and are not already rerouted.  The PLR also
   generates a MESSAGE_ID object (flags SHOULD be clear, Epoch and
   Message_Identifier MUST be set according to [RFC2961]).

   The PLR MUST generate a new Message_Identifier each time the contents
   of the B-SFRR-Ready Extended ASSOCIATION ID changes; for example,
   when PLR node changes the bypass tunnel assignment.

   The PLR node notifies the MP node of the bypass tunnel assignment via
   adding a B-SFRR-Ready Extended ASSOCIATION object and Association ID
   in the RSVP Path message for the protected LSP using procedures
   described in Section 3.4.

   The MP node acknowledges the PLR node assignment by signaling the B-
   SFRR-Ready Extended ASSOCIATION object and Association ID within the
   RSVP Resv message of the protected LSP.  With exception of the
   MESSAGE_ID objects, all other fields of the received in the B-SFRR-
   Ready Extended ASSOCIATION ID in the RSVP Path message are copied
   into the B-SFRR-Ready Extended ASSOCIATION ID to be added in the Resv
   message.  The MESSAGE_ID object is set according to [RFC2961] with

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   the Flags being clear.  A new Message_Identifier MUST be used to
   acknowledge an updated PLR assignment.

   The PLR considers the protected LSP as Summary FRR capable only if
   all the fields in the B-SFRR-Ready Extended ASSOCIATION ID that are
   sent in the RSVP Path message and the ones received in the RSVP Resv
   message (with exception of the MESSAGE_ID) match.  If it does not
   match, or if B-SFRR-Ready Extended ASSOCIATION object is absent in a
   subsequent refresh, the PLR node MUST consider the protected LSP as
   not Summary FRR capable.

3.2.  B-SFRR-Active Extended ASSOCIATION Object

   The Extended ASSOCIATION object for B-SFRR-Active association type is
   populated by a PLR node to indicate to the MP node (bypass tunnel
   destination) that one or more groups of protected LSPs that are being
   protected by the specified bypass tunnel are being rerouted over the
   bypass tunnel.

   The B-SFRR-Active Extended ASSOCIATION object is carried in the RSVP
   Path message of a bypass LSP and signaled downstream towards the MP
   (bypass LSP destination).

   The Association Type, Association ID, and Association Source MUST be
   set as defined in [RFC4872] for the ASSOCIATION Object.  More
   specifically:

   Association Source:

     The Association Source is set to an address of the PLR node.

   Association Type:

     A new Association Type is defined for B-SFRR-Active as follows:

     Value      Type
     -------    ------
     (TBD-2)    Bypass Summary FRR Active Association (B-SFRR-Active)

   Extended ASSOCIATION ID for B-SFRR-Active:

     The B-SFRR-Active Extended ASSOCIATION ID is
     populated by the PLR for the Bypass Summary FRR Active association.
     The rules to populate the Extended ASSOCIATION ID in this case are
     described below.

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3.2.1.  B-SFRR-Active Extended ASSOCIATION ID

   The Extended ASSOCIATION ID for the B-SFRR-Active association type
   has the following format:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |            Num-BGIDs          |          Reserved             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Bypass_Group_Identifier                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                               :                               |
      //                              :                              //
      |                               :                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Bypass_Group_Identifier                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           RSVP_HOP_Object                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           TIME_VALUES                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

          Figure 3: The Extended ASSOCIATION ID for B-SFRR-Active

   Num-BGIDs: 16 bits

      Number of Bypass_Group_Identifier fields.

   Reserved: 16 bits

      Reserved for future use.

   Bypass_Group_Identifier: 32 bits

      The Bypass_Group_Identifier that is previously signaled by the
      PLR using the Extended Association object.  One or
      more Bypass_Group_Identifiers may be included.

   RSVP_HOP_Object: Class 3, as defined by [RFC2205]

   Replacement RSVP HOP object to be applied to all LSPs associated
   with each of the following Bypass_Group_Identifiers. This corresponds
   to C-Type = 1 for IPv4 RSVP HOP, or C-Type = 2 for IPv6 RSVP HOP
   depending on the IP address family carried within the object.

   TIME_VALUES object: Class 5, as defined by [RFC2205]

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     Replacement TIME_VALUES object to be applied to all LSPs associated
     with each of the following Bypass_Group_Identifiers after receiving
     the B-SFRR-Active Extended ASSOCIATION Object.

3.3.  Signaling Procedures Prior to Failure

   Before Summary FRR procedures can be used, a handshake MUST be
   completed between the PLR and MP.  This handshake is performed using
   Extended ASSOCIATION object that carries the B-SFRR-Ready Extended
   Association ID in both the RSVP Path and Resv messages of the
   protected LSP.

3.3.1.  PLR Signaling Procedure

   The B-SFRR-Ready Extended ASSOCIATION object is added by each PLR in
   the RSVP Path message of the protected LSP to record the bypass
   tunnel assignment.  This object is updated every time the PLR updates
   the bypass tunnel assignment and that triggers an RSVP Path change
   message.

   Upon receiving an RSVP Resv message with B-SFRR-Ready Extended
   ASSOCIATION object, the PLR node checks if the expected subobjects
   from the B-SFRR-Ready ASSOCIATION ID are present.  If present, the
   PLR determines if the MP has acknowledged the current PLR assignment.

   To be a valid acknowledgement, the received B-SFRR-Ready ASSOCIATION
   ID contents within the RSVP Resv message of the protected LSP MUST
   match the latest B-SFRR-Ready Extended ASSOCIATION object and
   Association ID contents that the PLR node had sent within the RSVP
   Path message (with exception of the MESSAGE_ID).

   Note, when forwarding an RSVP Resv message upstream, the PLR node
   SHOULD remove any/all B-SFRR-Ready Extended ASSOCIATION objects whose
   Association Source matches the PLR node address.

3.3.2.  MP Signaling Procedure

   Upon receiving an RSVP Path message with a B-SFRR-Ready Extended
   ASSOCIATION object, the MP node processes all (there may be multiple
   PLRs for a single MP) B-SFRR-Ready Extended ASSOCIATION objects that
   have the MP node address as Bypass Destination address in the
   Association ID.

   The MP node first ensures the existence of the bypass tunnel and that
   the Bypass_Group_Identifier is not already FRR active.  That is, an
   LSP cannot join a group that is already FRR rerouted.

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   The MP node builds a mirrored Summary FRR Group database per PLR,
   which is determined using the Bypass_Source_Address field.  The
   MESSAGE_ID is extracted and recorded for the protected LSP PATH
   state.  The MP node signals a B-SFRR-Ready Extended Association
   object and Association ID in the RSVP Resv message of the protected
   LSP.  With exception of the MESSAGE_ID objects, all other fields of
   the received B-SFRR-Ready Extended ASSOCIATION object in the RSVP
   Path message are copied into the B-SFRR-Ready Extended ASSOCIATION
   object to be added in the Resv message.  The MESSAGE_ID object is set
   according to [RFC2961] with the Flags being clear.

   Note, an MP may receive more than one RSVP Path message with the B-
   SFRR-Ready Extended ASSOCIATION object from different upstream PLR
   node(s).  In this case, the MP node is expected to save all the
   received MESSAGE_IDs from the different upstream PLR node(s).  After
   a failure, the MP node determines and activates the associated
   Summary Refresh ID to use once it receives and processes the RSVP
   Path message containing B-SFRR-Active Extended ASSOCIATION object
   that is signaled over the bypass LSP from the PLR, as described
   Section 3.4

   When forwarding an RSVP Path message downstream, the MP SHOULD remove
   any/all B-SFRR-Ready Extended ASSOCIATION object(s) whose Association
   ID contains Bypass_Destination_Address matching the MP node address.

3.4.  Signaling Procedures Post Failure

   Upon detection of the fault (egress link or node failure) the PLR
   first performs the object modification procedures described by
   Section 6.4.3 of [RFC4090] for all affected protected LSPs.  For
   Summary FRR LSPs assigned to the same bypass tunnel a common RSVP_HOP
   and SENDER_TEMPLATE MUST be used.

   The PLR MUST signal non-Summary FRR enabled LSPs over the bypass
   tunnel before signaling the Summary FRR enabled LSPs.  This is needed
   to allow for the case when the PLR node has recently changed a bypass
   assignment and the MP has not processed the change yet.

   The B-SFRR-Active Extended ASSOCIATION object is sent within the RSVP
   Path message of the bypass LSP to reroute RSVP state of Summary FRR
   enabled LSPs.

3.4.1.  PLR Signaling Procedure

   After a failure event, when using the Summary FRR path signaling
   procedures, an individual RSVP Path message for each Summary FRR LSP
   is not signaled.  Instead, to reroute Summary FRR LSPs via the bypass

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   tunnel, the PLR adds the B-SFRR-Active Extended Association object in
   the RSVP Path message of the RSVP session of the bypass tunnel.

   The RSVP_HOP_Object field in the B-SFRR-Active Extended ASSOCIATION
   ID is set to the common RSVP_HOP that was used by the PLR in
   Section 3.4 of this document.

   The previously received MESSAGE_ID from the MP is activated.  As a
   result, the MP may refresh the protected rerouted RESV state using
   Summary Refresh procedures.

   For each affected Summary FRR group, its Bypass_Group_Identifier is
   added to B-SFRR-Active Extended ASSOCIATION ID.

3.4.2.  MP Signaling Procedure

   Upon receiving an RSVP Path message with a B-SFRR-Active Extended
   Association object, the MP performs normal merge point processing for
   each protected LSP associated with each Bypass_Group_Identifier, as
   if it received individual RSVP Path messages for the LSP.

   For each Summary FRR LSP being merged, the MP first modifies the Path
   state as follows:

   1.  The RSVP_HOP object is copied from the B-SFRR-Active Extended
       ASSOCIATION ID.

   2.  The TIME_VALUES object is copied from the TIMES_VALUE field in
       the B-SFRR-Active Extended ASSOCIATION ID.  The TIME_VALUES
       object contains the refresh time of the PLR to generate refreshes
       and that would have exchanged in a Path message sent to the MP
       after the failure when no SFRR procedures are in effect.

   3.  The SENDER_TEMPLATE object SrcAddress field is copied from the
       bypass tunnel SENDER_TEMPLATE object.  For the case where PLR is
       also the head-end, and SENDER_TEMPLATE SrcAddress of the
       protected LSP and bypass tunnel are the same, the MP MUST use the
       modified HOP Address field instead.

   4.  The ERO object is modified as per Section 6.4.4. of [RFC4090].
       Once the above modifications are completed, the MP then performs
       the merge processing as per [RFC4090].

   5.  The previously received MESSAGE_ID from the PLR is activated,
       meaning that the PLR may now refresh the protected rerouted PATH
       state using Summary Refresh procedures.

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   A failure during merge processing of any individual rerouted LSP MUST
   result in an RSVP Path Error message.

   An individual RSVP Resv message for each successfully merged Summary
   FRR LSP is not signaled.  The MP node SHOULD immediately use Summary
   Refresh procedures to refresh the protected LSP RESV state.

3.5.  Refreshing Summary FRR Active LSPs

   Refreshing of Summary FRR active LSPs is performed using Summary
   Refresh as defined by [RFC2961].

4.  Compatibility

   The (Extended) ASSOCIATION object is defined in [RFC4872] with a
   class number in the form 11bbbbbb, which ensures compatibility with
   non-supporting node(s).  Such nodes will ignore the object and
   forward it without modification.

5.  Security Considerations

   This document updates an existing RSVP object.  Thus, in the event of
   the interception of a signaling message, a slightly more information
   could be deduced about the state of the network than was previously
   the case.  Existing mechanisms for maintaining the integrity and
   authenticity of RSVP protocol messages [RFC2747] can be applied.
   Other considerations mentioned in [RFC4090] and [RFC5920] also apply.

6.  IANA Considerations

   IANA maintains the "Generalized Multi-Protocol Label Switching
   (GMPLS) Signaling Parameters" registry (see
   http://www.iana.org/assignments/gmpls-sig-parameters [1]).  The
   "Association Type" subregistry is included in this registry.

   This registry has been updated by new Association Type for Extended
   ASSOCIATION Object defined in this document as follows:

      Value  Name                         Reference
      -----  ----                         ---------
      TBD-1  B-SFRR-Ready Association     Section 3.1
      TBD-2  B-SFRR-Active Association    Section 3.2

   IANA also maintains and assigns the values for the RSVP-TE protocol
   parameters "Resource Reservation Protocol (RSVP) Parameters" (see
   http://www.iana.org/assignments/rsvp-parameters).

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7.  Acknowledgments

   The authors would like to thank Loa Andersson, Lou Berger, Eric
   Osborne, Gregory Mirsky, and Mach Chen for reviewing and providing
   valuable comments to this document.

8.  Contributors

      Nicholas Tan
      Arista Networks

      Email: ntan@arista.com

9.  References

9.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC2205]  Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and S.
              Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1
              Functional Specification", RFC 2205, DOI 10.17487/RFC2205,
              September 1997, <https://www.rfc-editor.org/info/rfc2205>.

   [RFC2747]  Baker, F., Lindell, B., and M. Talwar, "RSVP Cryptographic
              Authentication", RFC 2747, DOI 10.17487/RFC2747, January
              2000, <https://www.rfc-editor.org/info/rfc2747>.

   [RFC2961]  Berger, L., Gan, D., Swallow, G., Pan, P., Tommasi, F.,
              and S. Molendini, "RSVP Refresh Overhead Reduction
              Extensions", RFC 2961, DOI 10.17487/RFC2961, April 2001,
              <https://www.rfc-editor.org/info/rfc2961>.

   [RFC3209]  Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
              and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
              Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
              <https://www.rfc-editor.org/info/rfc3209>.

   [RFC4090]  Pan, P., Ed., Swallow, G., Ed., and A. Atlas, Ed., "Fast
              Reroute Extensions to RSVP-TE for LSP Tunnels", RFC 4090,
              DOI 10.17487/RFC4090, May 2005,
              <https://www.rfc-editor.org/info/rfc4090>.

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   [RFC4872]  Lang, J., Ed., Rekhter, Y., Ed., and D. Papadimitriou,
              Ed., "RSVP-TE Extensions in Support of End-to-End
              Generalized Multi-Protocol Label Switching (GMPLS)
              Recovery", RFC 4872, DOI 10.17487/RFC4872, May 2007,
              <https://www.rfc-editor.org/info/rfc4872>.

   [RFC6780]  Berger, L., Le Faucheur, F., and A. Narayanan, "RSVP
              ASSOCIATION Object Extensions", RFC 6780,
              DOI 10.17487/RFC6780, October 2012,
              <https://www.rfc-editor.org/info/rfc6780>.

9.2.  Informative References

   [RFC5920]  Fang, L., Ed., "Security Framework for MPLS and GMPLS
              Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010,
              <https://www.rfc-editor.org/info/rfc5920>.

9.3.  URIs

   [1] http://www.iana.org/assignments/gmpls-sig-parameters

Authors' Addresses

   Mike Taillon
   Cisco Systems, Inc.

   Email: mtaillon@cisco.com

   Tarek Saad (editor)
   Juniper Networks

   Email: tsaad@juniper.net

   Rakesh Gandhi
   Cisco Systems, Inc.

   Email: rgandhi@cisco.com

   Abhishek Deshmukh
   Juniper Networks

   Email: adeshmukh@juniper.net

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   Markus Jork
   128 Technology

   Email: mjork@128technology.com

   Vishnu Pavan Beeram
   Juniper Networks

   Email: vbeeram@juniper.net

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