How to config guarante bandwidth of Video Conference C2950G & C3600.(Polycom Device)
I recommend Low Latency Queueing for prioritizing video traffic. You can reference your extended access lists to the source and/or destination ip addresses of the video conferencing systems.
Here are a few CCO links..
Low Latency Queueing:
Low Latency Queueing for the VIP:
This is a complex question that requires more than BB post to answer. I suggest looking at the following link that explains QoS Strategy and configs for video in depth. http://www.cisco.com/en/US/tech/tk543/tk544/technologies_tech_note09186a0080094968.shtml