Subject: RE: MPLS PID

From: "David Allan" <[email-masked]>
Date: Wed, 2 Apr 2003 11:55:01 -0500

Curtis:

> I never knew that MPLS architecture was a religion.  I always 
> thought MPLS was deployed and because it solved real world 
> practical problems.

The above seems to be orthogonal to the discussion at hand :-(

> 
> Requiring the martinni control word would seem like a no 
> brainer. However maybe we don't buy into that for some 
> **technical** reason, perhaps overhead on the control word in 
> the edge of the network makes a difference.  If so, then the 
> control word must be added along the way if the traffic type is known.

My comment was more along the lines that if we accept ECMP as defacto, then
we have more to do than simply making sure PWs do not occasionally re-order.
IMHO it may solve some problems but would still be a major obstacle to
solving others.

> 
> The only truly deterministic way to know the traffic type is 
> if L3PID tells you.  

Yes, but as you note, that information is on a need to know basis and you
still end up inserting a dummy control word for those folks in the core that
will not be privy to this information. The core still expects stuff to self
identify.

BTW I presume you're exclusively discussing TE L3PID?

cheers
Dave