In one embodiment, a system includes a video mixer coupled with an audio
mixer for exchange of information that includes a first set of delay
values respecting input audio streams received by the audio mixer from a
plurality of source endpoints, and output audio streams sent from the
audio mixer to a plurality of destination endpoints. The information
further including a second set of delay values respecting the
corresponding input video streams. The audio mixer calculates end-to-end
video delays, and the video mixer calculates end-to-end audio delays. The
audio mixer delays the output audio streams to equalize the end-to-end
audio and video delays in the event that the end-to-end audio delays are
less than the end-to-end video delays, and the video mixer delays the
output video streams to equalize the end-to-end audio and video delays in
the event that the end-to-end video delays are less than the end-to-end
audio delays.