Abstract: A method for use in a multimedia conferencing arrangement to control multiple concurrent calls where each call comprises one or more channels. A first call among a first set of user stations and a second call among a second set of user stations are merged into a single call comprising a plurality of channels among at least three user stations from the first and second sets. The plurality of channels of the single, merged call corresponds to a combination of channels of the first and second calls and may include a signalling channel, a voice channel, and one data channel for each data channel of the first and second calls. The method is also applicable to calls including image or video channels.

Abstract: A transformation method for network conference connections where the network operations are determined based on stored information defining the original connection and stored information defining the target connection thus affording the opportunity to advantageously reuse existing paths. The paths to be deleted and the paths to be added to effect the transformation are determined such that no path is both deleted from and added to any switch. The connection information may be stored either in a central control entity or an intra-switch path information in the individual switches of the network. In the latter case, the individual switches determine their own intra-switch path additions and deletions in a distributed fashion.