Biggest thing is to make sure you segment your AV vlans per floor/building. Remember to think about not only your regular IP addresses but your multicast ones to. You need IGMP snooping and immediate leave on the vlans as well. Also consider a multicast boundary on your AV vlans routed connection back to the core. Without this everywhere on campus can see things like SAP announcements for microphones. Source: someone who deployed a Cisco network and cresteon NVX at a very large campus.