Introduction of one or more multicast engines to a video conferencing system permits an improvement of overall network bandwidth used for a video conference. Video streams are received at a multicast engine from each of at least two participants in the video conference. The multicast engine transmits only the first of the two video streams based on a determination that only the first video stream is a candidate for a conference video stream to be transmitted to at least some of a plurality of conference participants from the server station. The conference video stream is received at the multicast engine from the server station, and the stream is transmitted from the multicast engine to each of the participants in the video conference that are connected to the multicast engine.