The MPLS WG Archive

["Thomas D. Nadeau" <tnadeau@cisco.com>]

At 11:28 AM 12/13/2002 -0800, Kireeti Kompella wrote:
>Hi Tom,
>
>On Fri, 13 Dec 2002, Thomas D. Nadeau wrote:
>
> >
> >          It does seem plausible that RSVP-TE could signal
> > backup tunnels that could black hole traffic on the data plane
> > once switched on.  It is possible to do this at least in the facility-
> > based FRR mode, since a TE tunnel is signaled a priori (perhaps many
> > of  them), so one could go and test each to verify their health
> > to make sure that they are really protecting once turned on.
>
>(I appear to have an email *stack*, LIFO)
>
>As Curtis mentioned, the PLR can initiate such tests.

         Yes, my thinking exactly.

>Furthermore,
>the head end can test presignaled backup LSPs (alternate tunnel
>instances).

         Yes. I was thinking more of just letting the PLR test
the detours as it constructs them.  I can see how the head
end can also trace the LSP instances, but I think it is more
useful for the PLR to automatically do this if programmed,
as it seems more scalable.

>  All of these are left to the implementation to provide;
>perhaps after some experience, we will find that some enhancements to
>LSP ping to make this work better.

         Agreed.

         --Tom



"The difficult, we do immediately.  The impossible takes a little longer." 
-- Air Force Motto