Subject: MPLS-TE SESSION_ATTRIBUTE question

From: Paul Moore <[email-masked]>
Date: Thu, 08 Feb 2001 17:38:42 +0100

In section 4.7.4 of the RSVP-TE draft, it states (in the final paragraph
of the section):

"All RSVP routers, whether they support the SESSION_ATTRIBUTE
object

or not, SHALL forward the object unmodified.  The
presence of non-

RSVP routers anywhere between senders and receivers
has no impact on

this object."

This implies that non-RSVP routers should pass-through the PATH message.
However, section 4.2.5 states:

"RSVP is designed to cope gracefully with non-RSVP routers
anywhere

between senders and receivers. However, obviously, non-RSVP
routers

cannot convey labels via RSVP. This means that if a router
has a

neighbor that is known to not be RSVP capable, the router
MUST NOT

advertise the LABEL_REQUEST object when sending messages
that pass

through the non-RSVP routers.  The router SHOULD
send a PathErr back

to the sender, with the error code "Routing problem" and
the error

value "MPLS being negotiated, but a non-RSVP capable router
stands in

the path."

Is there a contradiction between these two statements? I suppose the
second statement in the first quoted paragraph above should simply be removed.
Or is there something I missed?

Also, an editorial comment concerning Section 4.7.4. The third-last
paragraph is incomplete.

Paul

--

Paul Moore

Alcatel Bell

+32 3 450 3536

[email-masked]