Distributed control teleconferencing voice bridge

DETAILED DESCRIPTION With the increased communications capabilities between computing devices, local area networks are being developed for interconnecting not just computers but many different voice, video and data communications devices.
Participants can view and manipulate shared multi-media information and can use conference voice capabilities to discusses the data that all view.
One such approach is provided in the multi-media conference system depicted in FIG.
1.
It is a computer-based "desk-to-desk" multi-media conferencing system that allows one or more groups of users to conference in video, audio and data in a flexible manner.
In effect, the user is placed in an "electronic meeting" room where most of the interactions that are carried on in a conventional conference are emulated.
In some respects, the system of FIG.
1 is more versatile than a real-life conference system in that users are able to select the conference in which they participate and the degree of participation, merely by providing the proper commands.
Describing the system of FIG.
1, each user interacts with equipment that is situated in some location, designated by block 5.
Generally, block 5 is the user's office, and all of the multi-media communication devices of the FIG.
1 system are in the user's office.
Only a telephone is shown in FIG.
1, but it is understood that many interface devices are possible.
An arrangement that includes more than just a computer is sometimes called a "workstation".
It is contemplated that each user has at least a computer 10, a telephone 30 and a telephone interface circuit 20.
Circuit 20 is connected to the user's telephone 30 and to a common conferencing voice bridge 40.
It also is connected to a conventional telephone line 14.
Computer 10 is connected via line 11 to interface circuit 20 and to voice bridge 40.
Computers 10 are also interconnected via Ethernet bus 15.
This interconnection creates a voice and data LAN arrangement.
The connection of computers 10 to the telephone interface circuit (e