Subject: RE: Two Drafts for Resilience of Control Plane

From: "Drake, John E" <[email-masked]>
Date: Sat, 29 Oct 2005 07:21:20 -0700

> Sticking to the example I described:
> a) absence of RSVP refreshes does not affect data plane in any way;
> b) use of LMP is not mandatory and, becides, I don't see now it helps.
> True, the TE link could be withdrawn, however, the LSP will still be
> operational
[JD] 

In your example, PathTear downstream and PathErr w/ state removed
upstream would work quite nicely.  As a matter of local policy, a node
always has the option of tearing down LSPs through adjacent nodes with
which control plane connectivity has been lost, after a configured
interval has elapsed.

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From: [email-masked]
Date: Sat, 29 Oct 2005 10:40:01 -0400 (EDT)

> upstream would work quite nicely.

True, but it means that operator needs to issue two management requests
from two controllers. But this is not how control plane is supposed to
work, isn't it? - it should be able to manage an LSP from a single
(usually, ingress)controller. The way you described it the operator needs
to figure out where to go and issue these requests. And what if this LSP
is not an S-PVC, rather, SVC created via UNI or ENNI request?

 As a matter of local policy, a node
> which control plane connectivity has been lost, after a configured

Sorry, for envirionments where control and data planes are not congruent
what you just said is an explicit NO-OPTION, i.e. must not be done - you
cannot destroy data plane just because you lost connectivity in the
control plane.

Igor