A protocol supporting distributed group and QoS management

Modern multimedia applications require new services from the communication systems. To negotiate and to manage the quality of service parameters, and in the case of collaborative work, to support synchronization and concurrency control, control information between the group members has to be exchanged. There are some approaches where a central group server supports the group and QoS management. To avoid the problems of central servers such as server failures and performance bottlenecks on the server side a distributed scheme for group and QoS management is more suitable. We present a protocol that supports distributed group and QoS management. The protocol is part of a conferencing system designed for applications of computer supported cooperative work. The system is based on the asynchronous transfer mode. The group communication protocol provides reliable, atomic and totally ordered delivery for a group of communicating partners. A design goal was simplicity to limit the overhead introduced by the group communication because the transmission and processing of video streams consumes a lot of bandwidth and processing power respectively.