Mikael Abrahamsson swmike at
Fri Nov 7 11:04:12 UTC 2008

On Fri, 7 Nov 2008, David Freedman wrote:

> Implementing this in an MPLS core is not an easy task, you can really 
> only do this on the edge, when the MPLS labelled packet arrives at an 
> LSR, we don't know if it contains a TCP segment or not (fancy deep h/w 
> implementations excluded), all we know is that , if there is congestion, 
> we can discard it based on the EXP bits in the shim.

I did some more checking and neither 12000 (IOS) nor CRS-1 seems to 
support WRED with ECN (at least the command doesn't show when I create a 
policy-map), so I'm going to ping my Cisco SE and hear about what's going 

Mikael Abrahamsson    email: swmike at

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