This document describes extensions to the 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
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.
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 LSPs.
Working Group Summary
no dissent reported (see PROTO writeup by Adrian Farrel)
Ross Callon reviewed this for the IESG. There are implementations
and it is reported that there is some deployment by "optical
vendors" (presumably optical switches).