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Fast Reroute Extensions to RSVP-TE for LSP Tunnels
RFC 4090

Document type: RFC - Proposed Standard (May 2005; No errata)
Document stream: IETF
Last updated: 2013-03-02
Other versions: plain text, pdf, html

IETF State: WG Document
Consensus: Unknown
Document shepherd: No shepherd assigned

IESG State: RFC 4090 (Proposed Standard)
Responsible AD: Alex Zinin
Send notices to: <swallow@cisco.com>, <loa@pi.se>

Network Working Group                                        P. Pan, Ed.
Request for Comments: 4090                            Hammerhead Systems
Category: Standards Track                                G. Swallow, Ed.
                                                           Cisco Systems
                                                           A. Atlas, Ed.
                                                           Avici Systems
                                                                May 2005

           Fast Reroute Extensions to RSVP-TE for LSP Tunnels

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.

Copyright Notice

   Copyright (C) The Internet Society (2005).

Abstract

   This document defines RSVP-TE extensions to establish backup label-
   switched path (LSP) tunnels for local repair of LSP tunnels.  These
   mechanisms enable the re-direction of traffic onto backup LSP tunnels
   in 10s of milliseconds, in the event of a failure.

   Two methods are defined here.  The one-to-one backup method creates
   detour LSPs for each protected LSP at each potential point of local
   repair.  The facility backup method creates a bypass tunnel to
   protect a potential failure point; by taking advantage of MPLS label
   stacking, this bypass tunnel can protect a set of LSPs that have
   similar backup constraints.  Both methods can be used to protect
   links and nodes during network failure.  The described behavior and
   extensions to RSVP allow nodes to implement either method or both and
   to interoperate in a mixed network.

Pan, et al.                 Standards Track                     [Page 1]
RFC 4090                  RSVP-TE Fast Reroute                  May 2005

Table of Contents

   1.  Introduction ...................................................3
       1.1.  Background ...............................................4
   2.  Terminology ....................................................4
   3.  Local Repair Techniques ........................................6
       3.1.  One-to-One Backup ........................................6
       3.2.  Facility Backup ..........................................7
   4.  RSVP Extensions ................................................8
       4.1.  FAST_REROUTE Object ......................................8
       4.2.  DETOUR Object ...........................................11
             4.2.1. DETOUR Object for IPv4 Address ...................11
             4.2.2. DETOUR Object for IPv6 Address ...................12
       4.3.  SESSION_ATTRIBUTE Flags .................................13
       4.4.  RRO IPv4/IPv6 Sub-object Flags ..........................14
   5.  Head-End Behavior .............................................15
   6.  Point of Local Repair (PLR) Behavior ..........................16
       6.1.  Signaling a Backup Path .................................17
             6.1.1. Backup Path Identification: Sender
                    Template-Specific ................................19
             6.1.2. Backup Path Identification: Path-Specific ........19
       6.2.  Procedures for Backup Path Computation ..................20
       6.3.  Signaling Backups for One-to-One Protection .............21
             6.3.1. Make-before-Break with Detour LSPs ...............22
             6.3.2. Message Handling .................................23
             6.3.3. Local Reroute of Traffic onto Detour LSP .........23
        6.4. Signaling for Facility Protection .......................24
             6.4.1. Discovering Downstream Labels ....................24
             6.4.2. Procedures for the PLR before Local Repair .......24
             6.4.3. Procedures for the PLR during Local Repair .......25
             6.4.4. Processing Backup Tunnel's ERO ...................26
        6.5. PLR Procedures during Local Repair ......................26
             6.5.1. Notification of Local Repair .....................26
             6.5.2. Revertive Behavior ...............................27
   7.  Merge Node Behavior ...........................................28
       7.1.  Handling Backup Path Messages before Failure ............28
             7.1.1. Merging Backup Paths using the Sender
                    Template-Specific Method .........................29
             7.1.2. Merging Detours using the Path-Specific Method ...29
             7.1.3. Message Handling for Merged Detours ..............31
       7.2.  Handling Failures .......................................31

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