How does quality-of-service (QoS) differ for video versus VoIP?
A. The Cisco recommendation is based on RFC 4594 (Configuration Guidelines for DiffServ Service Classes). Cisco recommends a 12-class service policy to include various forms of video traffic in addition to VoIP. In addition to a class for VoIP telephony, Broadcast Video (Video Surveillance/Enterprise TV), realtime interactive (Telepresence), multimedia conferencing (desktop collaboration) and multimedia streaming (VoDs/Digital Media System) are included. For IPVS, the media is marked DSCP CS5 and signaling is CS3. These can be marked by the either the camera or the Layer-2 switch. These value map nicely to the three-bit values for Layer-2 CoS and by default put IPVS in the appropriate ingress and egress switch queue.