Re: Your input: Use of PCE in Inter-domain

["Igor Bryskin" <ibryskin@movaz.com>]

The PCE-based architecture introduced in the draft provides probably the
only practical solution for computing of one or several disjoint paths for
TE tunnels spanning multiple TE advertising domains (IGP areas, ASs, etc.)

However, the limited TE visibility is not the only problem that can be
addressed by the proposed architecture. Generally speaking, it allows for
clear (logical and physical) separation of the path computation function
from the rest of (MPLS-based, GMPLS-based or any other dynamic) control
plane, which opens up numerous possibilities such as:

1) outsourcing of the path computation function by a controller that is not
capable to perform the function due to:
a) lack of information (does not run TE advertising protocol);
b) lack of software or computation resources;

2) making use of advanced path computation algorithms without upgrading
control plane software;

3) solving problems that require information more than usually available via
TE advertising protocols. Examples: global (re-)optimization of TE tunnel
placement, computing path for shared recovery (e.g. full mesh restoration),
etc.

4) making use of intensive NP-hard algorithms (e.g. multi-criteria
optimization, paths traversing multiple switching layers, paths satisfying
optical constraints with the re-generation loops, etc.)

Igor Bryskin,
Movaz networks

----- Original Message ----- 
From: "Adrian Farrel" <olddog@clara.co.uk>
To: <ccamp@ops.ietf.org>
Cc: <adrian@olddog.co.uk>
Sent: Tuesday, October 19, 2004 3:11 PM
Subject: Your input: Use of PCE in Inter-domain


> Folks,
>
> The chairs and ADs would like your input on
> http://www.ietf.org/internet-drafts/draft-ash-pce-architecture-00.txt in
the
> context of our inter-domain traffic engineering work.
>
> This draft documents an architecture for Path Computation Elements (PCE)
and
> is currently being discussed on the pce mailing list
> (https://www1.ietf.org/mailman/listinfo/pce)
>
> What we would like CCAMP to do is give us your opinion on whether PCE is
> addresing an inter-domain problem that needs to be addressed, and if so
> whether the architecture provides an acceptable way to resolve the
problem.
>
> Answers to the mailing list in advance of the meeting in Washington would
be
> appreciated.
>
> Thanks,
> Adrian and Kireeti
>
>
>
>
>