Systems and methods for conducting a multi-endpoint video signal
conference are provided. Conferencing endpoints are linked by pairs of a
reliable and a less reliable communication channel. Conference video
signals are scaleable coded in base layer and enhancement layers format.
Video signal base layers, which correspond to a minimum picture quality,
are communicated over reliable channels. The video signal enhancements
layers may be communicated over the less reliable channels. A conference
server mediates the switching of video layer information from
transmitting endpoints to receiving endpoints without any intermediate
coding or re-coding operations. The video conference can be integrated
with an audio conference using either scalable coded audio signals or
non-scaleable coded audio signals.