Issue for CCAMP meeting [Was: Early chair review of draft-ietf-ccamp-inter-domain-pd-path-comp-00.txt]

["Adrian Farrel" <adrian@olddog.co.uk>]

Hi Arthi,

[SNIPPED]

> hop at least has IP reachability (via IGP or BGP). If the next-hop is
> not reachable, then the path computation stops and the LSR sends back a
> PathErr upstream. If the next-hop is reachable, then it finds an
> ABR/ASBR to get to the next-hop. In the absence of an auto-discovery
> mechanism, the ABR in the case of inter-area TE or the ASBR in the
> next-hop AS in the case of inter-AS TE should be the loose next-hop in
> the ERO and hence should be accessible via the TED, otherwise the path
> computation for the inter-domain TE LSP will fail.
> ## I would like you to make it VERY clear what you are doing here.
> ## You are using the Routing Database to make TE routing decisions.
> ## This may (or may not) be OK in people's minds
> ## I will send separate mail to the CCAMP list because this is a BIG
> ## DEAL in GMPLS networks.

AA---> I noticed the mail that you sent out. Thanks! However, there have
been no replies yet. But I think this ID does state that that if the next
hop is not in the TED and does not have IP reachability, then such a
computation would fail. Should we raise this point again either at the
WG meeting or when we post the next rev ?


This would be a good topic to close at the meeting.
What you say here is OK: that is, if the hop is not in the TED *and* does
not have IP reachability, then computation fails.
Clearly, we also know what to do when the hop is in the TED (regardless of
IP reachability).

The issue we have to cover is what to do when the hop is *not* in the TED,
but we do have IP reachability.
What does this mean when we have a separate data and control plane? What
does it mean when the data and control planes are shared (as in MPLS)?
I think there may be some subtle operational issues hiding here and I feel
a BCP coming on :-(

If you could mention this in your slot, that would be valuable. If folks
with opinions could rush to the mic (or the mailing list), that would also
be helpful.

Cheers,
Adrian