Patent ID: 8411129

Claim:
A computer-implemented method, comprising: receiving registration messages at a call control agent device via first unicast transmissions from video conference terminals, the registration messages requesting set up of a video conference between the video conference terminals, wherein the video conference terminals comprise at least three video conference terminals; sending a set up message from the call control agent device to each of the video conference terminals via second unicast transmissions, wherein each set up message includes an identifier of a multicast control group that the video conference terminals are to join; determining, at the call control agent device, an active terminal of the video conference terminals based on audio data received from the video conference terminals; and sending a control message from the control agent device to the video conference terminals via the multicast control group in response to a determination that the active terminal has changed from a first video conference terminal to a second video conference terminal, wherein the control message enables the first video conference terminal to receive first video data via a first multicast group, wherein the control message enables the first video conference terminal to send second video data via a second multicast group, wherein the control message enables the second video conference terminal to send the first video data via the first multicast group, and wherein the control message enables the second video conference terminal to receive the second video data via the second multicast group.