SCALABILITY SUPPORT FOR MULTIPARTY MULTIMEDIA COMMUNICATIONS

In this paper, we propose a new communication abstraction known as the group channel which facilitates and supports the implementation of mu ltiparty interactive multimedia (MIM) applications such as video confe rencing. The group channel is a high-level abstraction for group commu nication. The credit scheme and the dynamic bandwidth calibration sche me are provided as an integral part of the group channel service for a llocating network bandwidth dynamically as participants join and leave the group channel. The multimedia transport protocol (MTP) is propose d as a realization of the group channel service in the ATM network. It s prototype implementation and a simple multiparty videoconferencing a pplication built on top of the MTP prototype are described in this pap er. Our results show that the group channel is capable of guaranteeing the performance of MIM applications irrespective of the group size an d differences in workstation speeds.