draft-ayyangar-ccamp-inter-domain-rsvp-te-00.txt

[Nagao Ogino <ogino@kddilabs.jp>]

Hi Arthi and Jean Philippe,

I have read your important draft titled "Inter domain MPLS Traffic 
Engineering- RSVP-TE extensions".
Your draft mentions MPLS-TE Fast Reroute for the inter-domain TE LSPs, and 
I have a question on the Fast Reroute in the inter-provider environment.

In the inter-provider case, each provider may confide the Route Record 
information of the inter-provider TE LSP established through the provider.
That is to say, each provider may not desire to disclose the route 
information within the provider.
(This may also need an extension of the RRO processing in the inter-domain 
RSVP-TE signaling.)

If so, the PLR  cannot recognize the NNHOP (MP) in the protection of the 
boundary LSR at the entry to a domain.
In your example topology, ASBR1 cannot recognize R3 and ASBR7 in the 
protection of ASBR4.
Thus, the PLR cannot establish the detour LSP because it has no information 
on the destination address of the detuor LSP.
In the same way, the PLR cannot find the bypass tunnel terminating at the 
NNHOP because it has no information on the NNHOP.

I thought that one of the solutions may be to establish the detour LSP in 
the reverse direction from the NNHOP to the PLR, and the NNHOP searches for 
the bypass tunnel terminating at the PLR. Those are possible because the 
NNHOP can recognize the PLR thanks to the advertisement of the 
inter-provider links.
In your example topology, R3 and ASBR7 can recognize ASBR1 thanks to the 
advertisement of the inter-provider link connecting ASBR1 and ASBR4.

In the protection of the boundary LSR at the exit of a domain, there is no 
problem because the PLR can recognize the NNHOP by the advertisement of the 
inter-provider links.

Is my understanding correct? Does my thought have a meaning?

Best regards,

Nagao Ogino
KDDI R&D Laboratories Inc.