Subject: Re: MPLS PID

From: Stewart Bryant <[email-masked]>
Date: Wed, 26 Mar 2003 13:06:36 +0000

Ron Cohen wrote:
> Stewart,
> 
> I'd like to defer the discussion on whether it was right or wrong for
> MPLS to have an MPLS PID or not to a different Email. I want to try and
> address the applications issue.
> 
> Suppose we do not adopt the 4 bit PID suggestion, and we use the 4 bits
> in the control word for other purposes. 
> 
> Lets look at the most problematic application, the IP load balancer.
> 
> A provider that has an MPLS core has two options:
> 
> 1. Run Pseudo-Wires on LSPs on which IP load balance is not enabled.

At the moment PW runs over any LSP between the PEs. To make this work
you would need to signal a special LSP and store state in the network
indicating that the forwarding path was different from the non-PW LSP.

> 2. Run Pseudo-Wires flows on top of IP.

Do we really want to revisit this can of worms?

> 
> Both options seems very reasonable for me. Why should a provider do
> otherwise?
> 

Stewart