A multipoint controller unit in which the audio signal processing is
distributed among several audio ports. The control of the audio signal
processing may be centrally or distributively managed by one or more
audio controllers. The audio signal processing may include selecting
audio streams from a common interface and/or mixing the signals from the
common interface. Each audio port may enhance the audio signal and
generate control information from the audio signal. The audio ports are
synchronized by a common information channel while the audio controllers
are synchronized by a common control channel interface. Port
fragmentation is reduced since the audio signal processing that relates
to an endpoint within a conference is handled by a single audio port.