Different technologies carry different forms of collaboration such as telephone conferencing, ISDN video conferencing, voice over IP, IP video conferencing, just to name a few. Improved real-time collaboration brings significant productivity and effectiveness to the system and to the communities. Multi-participant interactions allow users act together concurrently over the Internet to collaborate in a variety of applications such as conferencing, application sharing, collaborative design, tele-learning, tele-training, and many others. Many of these applications are synchronous, and must be carried out in a real-time fashion.