Abstract: A multimedia conferencing system, includes a multipoint control unit for distributing audio and video among a first set of n endpoints, where n?1, arranged in a star configuration, wherein bidirectional audio and video channels are established between said multipoint control unit and respective endpoints of said first set, and a second set of m endpoints, where m?2, connected to each other in a mesh configuration wherein bidirectional audio and video channels are established directly between the endpoints of the second set. Respective bidirectional video channels are established between the multipoint control unit and the respective endpoints of the second set. An audio hub is connected to the multipoint control unit over one or more bidirectional audio channels and connected to the second set of endpoints via respective bidirectional audio channels. The audio hub transfers audio between the second set of endpoints and the multipoint control unit over a common bidirectional audio channel.