Re: OSPF inter-AS extensions for GMPLS (RFC5392) questions

"Adrian Farrel" <adrian@olddog.co.uk> Thu, 05 March 2009 09:49 UTC

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From: "Adrian Farrel" <adrian@olddog.co.uk>
To: "Fabien Verhaeghe" <fabien.verhaeghe@marben-products.com>, <ccamp@ops.ietf.org>
Subject: Re: OSPF inter-AS extensions for GMPLS (RFC5392) questions
Date: Thu, 5 Mar 2009 09:49:11 -0000
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Hi Fabien,

> Sorry to come a little late on this but I have a question on inter-AS
> extensions RFC5392 (also applicable on ISIS extensions).
> In section 4:
> " Only some essential TE information for the link needs to be
>   advertised; i.e., the Link Type, the Remote AS number, and the Remote
>   ASBR ID."
>
> First what does "remote" mean here? is it remote in the context of the
> proxied link or in the context of the Router?
> i.e.
>
> RouterA in AS1 ------TE Link------ RouterB in AS2
>
> I guess it is in the context of the link. That is in LSA generated by 
> router
> A for B->A link (proxied) we put AS1 and routerA ASBR Id. Is that correct?

Yeah, you could say "in the context of the router." Or even "in the context 
of the IGP instance". Since the IGP will only be running in one AS, the 
advertising router is talking about the IDs of the "other" AS and ASBR.

> Second question: I'm not sure about the purpose of "only some essential TE
> information for the link needs to be advertised" sentence.
> Does it mean it not allowed to put other information like bandwidth,
> protection type? (in case the link has asymetric characteristic)
> Besides I think another essential information is the remote link Id or
> remote IP address in order to correlate the proxied B->A link with the 
> A->B
> link.
> Do you agree?

Perhaps the text is a bit vague here. I would use the rest of the document 
that contains definitions of which sub-TLVs are allowed.

A