Subject: Re: GMPLS/RSVP-TE question + Comments on GMPLS last call

From: "Yuri Landry" <[email-masked]>
Date: Fri, 18 May 2001 14:32:41 -0000

Cheenu,

>We want to set up an LSP A-1-B-2-C and signal it via RSVP-TE. The ERO
>should be (A-1, B-2, C). However, a Path message can only be sent
>out link A-D and has to be routed towards B; it cannot be sent
>down link 1 since 1 is not IP-capable. Is this ok? What kind of
>Path state is created on D? Or, do we need to tunnel the Path
>message to B directly? Will D change the PHOP object to point
>to itself (we do not want D to change the contents of the ERO)? In
>this case when B receives this message it will find that the
>Path came to it from an interface that is not part of the ERO. Is
>this an error?

In your case, A need to put B as the destination address in the RSVP-TE 
message and turn off the router alert option.

Your question actually reminds me what's missing in the GMPLS drafts: the 
scope and applicability statment.

I am very glad to see that more folks realize that the control plane may be 
distinct from a data plane topology in optical networks. This is only one of 
many distinctions between IP network and optical network. GMPLS siganaling 
drafts so far only cover a set of new TLVs/Objects. In case we implement the 
GMPLS drafts exactly, I doubt that they work for optical network. There are 
tons of issues that haven't been solved yet. For example, if the control 
channel fails, what we should do to the associated circut connections 
etc.etc.

In order to be clear and not misleading, I hope that the current GMPLS 
signaling drafts has a clear statement of what it covers and what it hasn't. 
I'd like to see:

(1) Scope: It is only for intra-domain

(2) Content: It defines a set of new TLVs/Objects which are not exhaustive

(3) What's Missing: It doesn't cover protocol mechanisms related issues. 
Modifications of MPLS signaling protocol mechanisms are need for GMPLS 
signling to be applicable to optical network.

(4) What are other related draft: For example, in order for GMPLS RSVP-TE to 
work for optical network, at leaset Refreshment reduction need to be 
supported etc.

Regards,

Yuri

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