QoS 8025 Video Conferencing setup

Do have an end-to-end QOS policy, or are you only trying to accomplish QoS at the iDirect layer?  If you are only using the iDirect layer, you will need to take your plan/policys to your border routers and beyond.  An end-to-end solution is tedious but they are the most effective.  Accomplishing it on the iDirect (although it would be nice if it were that easy) is simply not enough, as your traffic is probably getting lost in the router queuing, or simply ending up behind "other" (default) traffic) on the routers.    In the case of TCP it often ends up out of sequence.  However in your case it is UDP (fire and forget unreliable).    My guess is you are bottlenecking at the routers....Ingress and egress.

Suggest you break out the wireshark/ethereal and sniff the path...that should help you find your bottleneck.