Extensions to GMPLS Resource Reservation Protocol (RSVP) Graceful Restart
RFC 5063

Network Working Group                              A. Satyanarayana, Ed.
Request for Comments: 5063                                R. Rahman, Ed.
Updates: 2961, 3473                                        Cisco Systems
Category: Standards Track                                   October 2007

        Extensions to GMPLS Resource Reservation Protocol (RSVP)
                            Graceful Restart

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Abstract

   This document describes extensions to the Resource Reservation
   Protocol (RSVP) Graceful Restart mechanisms defined in RFC 3473.  The
   extensions enable the recovery of RSVP signaling state based on the
   Path message last sent by the node being restarted.

   Previously defined Graceful Restart mechanisms, also called recovery
   from nodal faults, permit recovery of signaling state from adjacent
   nodes when the data plane has retained the associated forwarding
   state across a restart.  Those mechanisms do not fully support
   signaling state recovery on ingress nodes or recovery of all RSVP
   objects.

   The extensions defined in this document build on the RSVP Hello
   extensions defined in RFC 3209, and extensions for state recovery on
   nodal faults defined in RFC 3473.  Using these extensions, the
   restarting node can recover all previously transmitted Path state,
   including the Explicit Route Object and the downstream (outgoing)
   interface identifiers.  The extensions can also be used to recover
   signaling state after the restart of an ingress node.

   These extensions are not used to create or restore data plane state.

   The extensions optionally support the use of Summary Refresh, defined
   in RFC 2961, to reduce the number of messages exchanged during the
   Recovery Phase when the restarting node has recovered signaling state
   locally for one or more Label Switched Paths (LSPs).

Satyanarayana & Rahman      Standards Track                     [Page 1]
RFC 5063         GMPLS RSVP Graceful Restart Extensions     October 2007

   Table of Contents

   1. Introduction ....................................................3
   2. Conventions Used in This Document ...............................5
   3. Terminology .....................................................5
   4. Extensions to Nodal Fault Handling ..............................5
      4.1. RecoveryPath Message Format ................................5
      4.2. Capability Object ..........................................6
           4.2.1. Conformance .........................................7
      4.3. Related Procedures .........................................7
      4.4. Procedures for the Capability Object .......................8
           4.4.1. Procedures for the Downstream Neighbor ..............8
           4.4.2. Procedures for the Restarting Node ..................8
      4.5. Procedures for the RecoveryPath Message ....................9
           4.5.1. Procedures for the Downstream Neighbor ..............9
           4.5.2. Procedures for the Restarting Node .................10
                  4.5.2.1. Path and RecoveryPath Message Procedures ..11
                  4.5.2.2. Re-Synchronization Procedures .............12
                  4.5.2.3. Procedures on Expiration of
                           Recovery Period ...........................13
      4.6. Compatibility .............................................13
   5. RecoveryPath Summary Refresh ...................................14
      5.1. MESSAGE_ID ACK/NACK and MESSAGE_ID LIST Objects ...........15
      5.2. RecoveryPath Srefresh Capable Bit .........................16
           5.2.1. Procedures .........................................16
           5.2.2. Compatibility ......................................17
      5.3. RecoveryPath Summary Refresh Procedures ...................17
           5.3.1. Generation of RecoveryPath-Related Srefresh
                  Messages ...........................................17
           5.3.2. RecoveryPath-Related Srefresh Receive
                  Processing and NACK Generation .....................19
           5.3.3. RecoveryPath-Related MESSAGE_ID NACK
                  Receive Processing .................................19
   6. Security Considerations ........................................20
   7. Acknowledgments ................................................21
   8. IANA Considerations ............................................21
   9. Normative References ...........................................22