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RE: Last call - RSVP problems
Hi Jonathan,
One point to consider is that the signaling control
channel might be realized over a different link layer
than LMP. For example, LMP might be running in-fiber
over SONET/SDH overhead bytes, while RSVP is running
over an out-of-band network such a shared Ethernet.
RSVP Hello allows independent detection of signaling
channel failure, so it's a useful option to keep.
Thanks,
Dimitris
Dimitris Pendarakis
Tellium, Inc.
> -----Original Message-----
> From: Jonathan Lang [mailto:jplang@calient.net]
> Sent: Friday, May 25, 2001 5:30 PM
> To: 'Fong Liaw'; 'suresh Katukam'; v.sharma@ieee.org
> Cc: 'Jennifer Yates'; mpls@UU.NET; ccamp@ops.ietf.org
> Subject: RE: Last call - RSVP problems
>
>
> Fong,
>
>
> <snip>
> > Same as (2), any proposals that remove the refresh mechanism
> > is going to be difficult to prove that all cases are covered.
> >
> > Instead, we (will) recommend the following in OIF UNI document:
> >
> > Use RSVP Hello to detect control channel failure.
> Why wouldn't you use the LMP Hello to detect control channel
> failure? This
> is exactly what it is designed for. From
> draft-ietf-mpls-lsp-tunnel-08.txt,
>
> "This (RSVP Hello) mechanism is intended to be used when
> notification of
> link layer
> failures is not available and unnumbered links are not
> used, or when
> the failure detection mechanisms provided by the link layer are not
> sufficient for timely node failure detection."
>
> > If a control channel failure is detected, LSPs states
> > are maintained as if a node continues to receive
> > RSVP refresh message from the failed control channel.
> > The recommended Hello timer will be in second range,
> > instead of ms range specified in RSVP-TE draft.
> >
> > If a control channel failed permanently, manual intervention
> > may be required. This is to be studied.
> >
> > p.s The text is currently being drafted as we type.
>