Distributed video conferencing systems

The emergence of the Internet as a global communications infrastructure has enabled the development of new distributed multiparty video conferencing solutions. These distributed solutions differ considerably from the circuit-switched centralized approaches which preceded them. In this paper we discuss these differences from a general perspective and then describe an actual distributed multiparty solution. The multimedia multiparty teleconferencing (MMT) system implemented at the IBM T.J. Watson Research Center is a high quality video conferencing solution that runs over an IP network. The solution addresses multicast, synchronization, video mixing, error handling, and directory service issues. A detailed description of a solution for secure video conferencing through corporate firewalls is presented. © 1997 Elsevier Science B.V.