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Re: Proposed strategy for Inter-area/AS


Jean-Louis

I think this is a good strategy.

Thanks!

I think we're pretty close to agreement on the points you raise.
It may not have been apparent from my original email that I am NOT suggesting the work in one phase must complete before the work on the next phase can start. I am, however, saying that I expect the work to start in the order shown.
This is not unreasonable and should reflect the natural processes anyway.

I have two comments:

1) As already mentionned by Vishal, we cannot,
IMHO, decorrelate 6 from 1, 2 3 and 5.
-The support of additional functions may require important
modifications, if they are not taken into account during the
initial step of specifications.
-Path Reoptimization is a MUST requirement and Path diversity is a
SHOULD requirement ( inter-area and inter-as reqt drafts). So we
should not address them as advanced functions, but rather as base
functions of the inter-area/AS tool-kit. 

2) I'm not sure to well understand what do you put in 3.
What do you exaclty mean by routing model, and how do you
distinguish it from the path computation model ?

Perhaps I should have said "distibution of TE and other information
by the routing protocol or by other means". This is not path
computation. 

Requirement drafts clearly point out that routing (IGP, EGP)
extensions should be avoided, except some minor extensions to
advertise static parameters such as PCS capabilities for instance
(addressed in point 5).

I am not sure that I can find any text in the two TEWG drafts that actually says what you suggest.
There are comments on scalability which are, of course, related.
There are also lots of comments about TE aggregation which might be considered as extensions.

Regardless of how or where the path is computed the full system must have visibility across the whole of the system. This may be compartmentalised and restricted to domains relying on crankback, it may use cooperative PCEs, it may use some leakage of (aggregated) TE information. What is up for debate is closely linked to the choice of computation point(s) and focuses on what information is distributed and how.

Hope this will help.

Very much appreciate your support and opinions.

Cheers,
Adrian