IP QoS case-studies

I've found there's no shortage of advice and theory about
the viability of IP QoS (DiffServ) in a large wide-area
(converged) network.

I have not had much luck with finding documentation about
experiences implementing and operating such a beast.
Presumably that's yet another (silent) confirmation that It
Doesn't Work or There's a Better/Easier Way.

Nevertheless, I'd still like to find anyone who has tried
(successfully or not) to converge (ie VoIP/H.323/data) a
high-speed (~ 1Gb/s) IP network and use IP QoS for what it
is sold to do. White paper/presentation references or
off-line conversation would be appreciated.



There was an article in the last network world about Worldcom using DiffServ
in its VPN offering, and I found this article as well: