Subject: [Pce] PCEP requirement to support RWA

From: Young Lee <[email-masked]>
Date: Fri, 06 Feb 2009 14:35:32 -0600

Hello PCErs, while WSON RWA has been moving steadily forward at CCAMP we
seem to be stuck in getting the necessary enhancements to PCEP. There has
been some discussion that our PCEP WSON RWA requirements may be general
GMPLS requirements.

If so we'd be happy to incorporate them into a GMPLS requirements document,
however we're not sure if these would then become a burden for non-WSON
GMPLS networks. PCE is crucial to the control of WSON we'd like to get this
hammered out prior to the San Francisco meeting.

A quick summary of WSON requirements (in term of label assignment):

(a) There are currently two accepted WSON architectural options R&WA and 

R+Distributed WA. One requires wavelength assignment one doesn't.  Hence

we need in our Request message the ability to ask for label assignment or
not.

(b) Laser transmitters maybe tunable with limited ranges. Hence we need in
our Request message the ability to specify  that a restricted label range is
required.

(c) PCEP currently allows us to specify if we desire a bidirectional LSP. In
WSONs we may have the additional need to specify that the wavelengths
(labels) used in both directions should be the same (or not).

(d) PCEP supports re-optimization. One useful type of re-optimization for
WSONs is the ability to change the wavelength assignment without changing
the route. This is also similar to a third WSON architectural option (not
required) where one PCE that computes routes asks another for wavelength
assignment (WA).

Comments and suggestions are invited and encouraged

Best Regards

Young L. and Greg B.