Subject: RE: draft-ashwood-ccacmp-gmpls-constraints

From: "Ong, Lyndon" <[email-masked]>
Date: Thu, 4 Aug 2005 05:51:41 -0400

Hi Igor,

I was wondering also about using a virtual link model, that seems to 
be able to carry similar or more information, with maybe a bit more
overhead.

Cheers,

Lyndon 

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On
Behalf Of [email-masked]
Sent: Thursday, August 04, 2005 2:32 AM
To: Don Fedyk
Cc: [email-masked]
Subject: Re: draft-ashwood-ccacmp-gmpls-constraints

Hi,

I believe this is a very useful draft. The described blocking problem (a
limited ability of a node to cross-connect resources on input and output
links wrt a particular LSP) exists not only in the Virtual Node
scenario:
there could be "real" network elements experiencing the problem
(perhaps, because of the hardware limitations). Hence there is a need
for a routing controller to be capable to advertise a map of acceptable
(or
unacceptable) input-output link combinations, and for a path computer to
account for such a constraint (which is not trivial).

I also would suggest the authors to consider the Virtual Link mode, that
is, representing the domain to the outside world as a bunch of PEs
interconnected by abstract (virtual) links. This approach may require
more advertisements compared to the Virtual Node mode; however, it does
relieve external path computers from handling the interface maps, plus
it gives the idea about the cost and attributes of feasible paths across
the domain.

Igor

>
> Since we did not get through all the CCAMP agenda today, I would still

> like to get feedback on the following draft.
>
> Link Viability Constraints Don Fedyk (5 mins) 
> http://home.clara.net/olddog/63/draft-ashwood-ccamp-gmpls-constraint-r
> eq
> ts-00.ppt
> http://www.ietf.org/internet-drafts/draft-ashwood-ccamp-gmpls-constrai
> nt
> -reqts-00.txt
>
> Note the draft is about interfacing a dynamic optical system to a 
> GMPLS control plane but puts forward the argument we can avoid for now

> the standardization of the detailed optical constraints.  I would like

> to see this in Scope for the IETF (CCAMP) even though I realize the 
> detailed (or complex) optical constraints may be years from being in 
> scope and standardization. The current draft is a requirements draft 
> with some preliminary ideas on how this can be achieved. I would like 
> to solicit others who are interested in working this problem.
>
> Please send feedback, I'm around till Friday if anyone would like to 
> discuss in person, Thanks, Don
>
>
>
>
>
>