Multimedia mail in teleconferencing system

A teleconferencing system that integrates separate real-time and asynchronous networks - the former for real-time audio and video, and the latter for control signals and textual, graphical and other data - in a manner which closely approximates the experience of face-to-face collaboration. The system provides an audio/video (AV) path (13) for carrying AV signal among the workstations, a video mosaic generator (36) for combining images, and an audio summer or mixer (38). At least part of the AV path (13b) is implemented with unshielded twisted pair wiring. The system architecture is readily scalable to the largest enterprise network environments. It accommodates differing levels of collaborative capabilities available to individual users and permits high-quality audio and video capabilities to be readily superimposed onto existing personal computers and workstations (12) and their interconnecting LANs (10) and WANs (15). In the case of a plurality of geographically dispersed LANs (10) interconnected by a WAN (15), the demands made on the WAN are significantly reduced by employing multi-hopping techniques, including avoiding the unnecessary decompression of data at intermediate hops, as well as video mosaicing and cut-and-paste technology.