Multicast system capable of dividing entire group into plural groups with easier procedures

摘要

A conference terminal is incorporated in a multicast conferencing system. The conference terminal receives a request for division into groups. The request includes information indicating that the terminal belongs to which group. The terminal then produces, in response to the request, only the stream data coming from one or more other conference terminals belonging to the same group as the terminal. This production is realized by selectively accepting such stream data at a reception unit to which all stream data are transmitted from all the terminals having the same multicast address. Alternatively, the production is realized by selectively re-writing stream data at a scene re-writer. Thus, the produced stream data are replayed and displayed. The division of an entire group into plural small groups can be performed without additionally issuing multicast addresses.