Patent ID: 7693190

Claim:
A method comprising: receiving, by a video mixer, information from an audio mixer that includes delay values respecting input audio streams received by the audio mixer from a plurality of source endpoints, and output audio streams sent without timestamps from the audio mixer to a plurality of destination endpoints that do not extract Real-Time Transport Control Protocol (RTCP) packets, each input and output audio stream being respectively associated with a corresponding input and output video stream, the video mixer and the audio mixer being physically located at different places on a communication network; calculating, from the information received, an output delay value for each corresponding output video stream to ensure that source endpoint-to-destination endpoint audio and video delays are substantially equal; buffering, by the video mixer, each of the corresponding input and output video streams; and adjusting the buffering of each of the corresponding input and output video streams so as to delay each corresponding output video stream by the output delay value.