mpls draft-ietf-mpls-ldp-ft-01.txt

["Philip Matthews" <philipma@nortelnetworks.com>]

NAME OF I-D:

   http://www.ietf.org/internet-drafts/draft-ietf-mpls-ldp-ft-01.txt


SUMMARY

   MPLS systems will be used in core networks where system downtime
   must be kept to an absolute minimum.  Many MPLS LSRs may, therefore,
   exploit Fault Tolerant (FT) hardware or software to provide
   high availability of the core networks.

   This document identifies issues in the LDP specification that make it
   difficult to implement an Fault Tolerant LSR using the current LDP protocol, 
   and proposes enhancements to the LDP specification to ease
   such FT LSR implementations. The extensions are equally applicable to CR-LDP.


RELATED DOCUMENTS

   http://www.ietf.org/internet-drafts/draft-ietf-idr-restart-00.txt
       Describes a Fault Tolerance scheme for BGP.

   http://www.ietf.org/internet-drafts/draft-ietf-ospf-hitless-restart-00.txt
       Describes a Fault Tolerance scheme for OSPF. There were two schemes presented
       at the last OSPF WG meeting; this is the scheme that the OSPF WG preferred.
 

WHERE DOES IT FIT IN THE PICTURE OF THE SUB-IP WORK

    The procedures described in this document are specific to MPLS (specifically
    LDP and its extension CR-LDP).

    They are not directly applicable to other protocols, though similar procedures
    can be defined for other TCP-based protocols.


WHY IS IT TARGETED AT THIS WG

   Fault Tolerance is explicitly listed as a work item in the current
   MPLS WG charter  ( http://www.ietf.org/html.charters/mpls-charter.html ):
      "The current goals of the working group are: 
         [snip]
         Standards Track: 
         [snip]
         5. Specify improved fault tolerance mechanisms for LDP.
      "

   This I-D completely addresses this work item. In fact, the acceptance
   of this document by the WG as a WG document was the reason
   that this work item was added to the WG charter.


JUSTIFICATION

   This document was accepted a year ago by the MPLS WG as a charter item,
   and has recently gone through a WG last call with only minor comments.

- Philip