Group Management Services for Distributed Multimedia Applications

1. Introduction In today's computer network environments there is an increasing need to be able to connect named groups of people and/ or processes that need to collaborate to carry out some activity. We are concerned with the communication of multimedia information amongst distributed group members, and this places heavy demands on systems infrastructures and networks. In current multimedia environments, the developers of group applications are forced explicitly to manage group membership, group characteristics, connection establishment, dynamic conference control and synchronisation [Garcia 93]. Ideally, however, applications developers should be left free to concentrate on the semantics of the application [Trevor 95]; if a class of application requires a certain functionality or quality of service, the lower layers should provide it [Verissimo 92]. Apart from freeing the user from the burden of providing these services, such lower layers can be specially optimised and thoroughly tested. In this paper, we provide an overview of the requirements of multimedia group applications and suggest an architecture for a set of Group Management Services (GMS) intended to provide generic system level support for this class of application. Implementation work on the GMS being carried out at Lancaster University is also described