ATM RendezView: multipoint conferencing on ATM

Abstract

ATM RendezView is a prototype application which takes a radical shift in thinking to provide a high quality, distributed, multiparty video conferencing environment. No longer are media stream bridging, mixing and distribution functions resident in a centrally located multipoint control unit (MCU), but are distributed among end-systems. Asynchronous transfer mode (ATM) is instrumental to the success of the prototype since it provides dynamic point-to-multipoint switched virtual connections (SVCs) for media stream distribution, each connection having a negotiable quality of service (QoS). Dynamic point-to-multipoint connections empower each conferee to independently choose particular media streams to be received from other conferees, thus affording the function of switched presence control. Processing intensive functions such as audio mixing and video decoding are off-loaded onto the end-systems which exploit real-time facilities such as threads and real-time scheduling to meet processing deadlines.