Subject: RE: RSVP Graceful Restart

From: Nic Neate <[email-masked]>
Date: Wed, 22 Oct 2003 16:40:55 +0100

All,

Together with some colleagues at Data Connection, I have done some work
looking at how GMPLS Restart could work with RSVP Fast Reroute LSPs.  While
Restart was originally intended as a recovery mechanism for optical networks
and Fast Reroute more as a packet network protection scheme, they do both
provide data traffic preservation mechanisms that could be usefully deployed
in the same network.  We'd be interested in working with anyone looking at
progressing a solution for this.

There are various complications in recovering RSVP state when a node
supporting backup LSPs restarts, in particular following a failure of the
upstream or downstream protected LSP.  New mechanisms will be required to
reconstruct the FAST_REROUTE, DETOUR, ERO, RRO, SENDER_TSPEC, FLOWSPEC and
SESSION_ATTRIBUTES objects.

Again, we've got some ideas on this.  What is the general level of interest
in this area?

Nic

-----Original Message-----
From: Seabridge - Nurit Sprecher
Sent: Wednesday, October 22, 2003 10:43 AM
To: [email-masked]'; [email-masked]'; [email-masked]'
Cc: [email-masked]'; [email-masked]'
Subject: RSVP Graceful Restart

Hi,
I did not have the chance yet to read the draft, but I really believe there
is a need to extend the general description in the GMPL document.
I hope that you new definition for the ERO recovery would help also to let
the Ingress LER to recover.

One more thing that I would like to see in the extension, is how graceful
restart works together with Fast Reroute Protection. Specifically the
problematic points are the MP and the PLR. Do you have any intention to
cover it as well?

Thanks in advance, Nurit.

---

From: Kireeti Kompella <[email-masked]>
Date: Fri, 24 Oct 2003 11:39:44 -0700 (PDT)

Hi Nic,

On Wed, 22 Oct 2003, Nic Neate wrote:

> looking at how GMPLS Restart could work with RSVP Fast Reroute LSPs.

FRR and GR solve *very* different problems: the first is for link or
node failures where the data plane is affected, the second for control
plane failures (a special subset of node failures).

Could you explain the problem you see here?

Kireeti.