Thanks Patrick. Indeed, we have settled on CS4 for our videoconferencing media flows and CS3 for our signalling simply as the organisations we manage do no utilise actual Telepresence systems (and are unlikely to do so), and we want to distinguish our traffic from other interactive video such as web conferencing. We would then recommend that the priority queue would be set for EF+CS4+CS5 traffic, with the next queue looking after the likes of CS3 and AF41 traffic.
However, this still dosen't quite answer the question with regard to whether the VCS actually overwrites the tags on flows through it (if already set) or leaves pre-tagged traffic alone. As the VCS has only a single global QoS value, I assume that if it were set to CS4 (DSCP value 32), then if the endpoint were actually set with CS4 on the media and CS3 on the signalling, then the VCS would actually overwrite the signalling packet headers. This then seems a bit pointless that you can set different QoS tags to different traffic at the endpoint (or elsewhere for that matter) only for them to be overwritten.
The administration guide makes no indication as to what the VCS will actually do, just that the single global value will be applied to both media and signalling traffic.
Cheers,
Chris
