Network Working Group                                        R. Aggarwal
Internet Draft                                          Juniper Networks
Intended Status: Standards Track
Updates: 1122                                                K. Kompella
Expiration Date: December 17, 2008                      Juniper Networks

                                                               T. Nadeau
                                                                      BT

                                                              G. Swallow
                                                     Cisco Systems, Inc.

                                                           June 20, 2008


                           BFD For MPLS LSPs


                       draft-ietf-bfd-mpls-07.txt

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Raggarwa                                                        [Page 1]

Internet Draft         draft-ietf-bfd-mpls-07.txt              June 2008


Abstract

   One desirable application of Bi-directional Forwarding Detection
   (BFD) is to detect a Multi Protocol Label Switched (MPLS) Label
   Switched Path (LSP) data plane failure. LSP-Ping is an existing
   mechanism for detecting MPLS data plane failures and for verifying
   the MPLS LSP data plane against the control plane. BFD can be used
   for the former, but not for the latter. However the control plane
   processing required for BFD control packets is relatively smaller
   than the processing required for LSP-Ping messages. A combination of
   LSP-Ping and BFD can be used to provide faster data plane failure
   detection and/or make it possible to provide such detection on a
   greater number of LSPs. This document describes the applicability of
   BFD in relation to LSP-Ping for this application. It also describes
   procedures for using BFD in this environment.



Table of Contents

 1          Specification of requirements  .........................   3
 2          Introduction  ..........................................   3
 3          Applicability  .........................................   3
 3.1        BFD for MPLS LSPs: Motivation  .........................   3
 3.2        Using BFD in Conjunction with LSP-Ping  ................   5
 4          Theory of Operation  ...................................   6
 5          Initialization and Demultiplexing  .....................   7
 6          Session Establishment  .................................   7
 6.1        BFD Discriminator TLV in LSP-Ping  .....................   8
 7          Encapsulation  .........................................   8
 8          Security Considerations  ...............................   9
 9          IANA Considerations  ...................................  10
10          Acknowledgments  .......................................  10