Hi Siva
Do you need access restrictions based on specific time-periods on a regular basis , or are the video conferencing requests adhoc ? If it is adhoc, then you cant do much with ACL's... If it is time based on specific days, you can implement time based ACL's and restrict bandwidth to an extent.. Eitherways, if you have QOS configured with Custom based classifiers, you can prioritize video, and give it a bandwidth cap, when the traffic is on... You can look at various qos strategies to have this in place... bandwidth management tools adds additional active devices on network, and can do this for you , but you have to justify why you need that on your network.
Hope this helps.. all the best
Raj
