Multicast communication facilities for distributed multimedia information systems

A typical Distributed Multimedia Information System (DMIS) is made up of clusters of workstations connected by local area networks. Such a system allows users to exchange information in the form of integrated documents containing text, graphics and voice. Recently, there have been proposals for such systems which support both store-and-forward (e.g. mail) and real-time material (e.g. conferencing). The efficiency of a DMIS relies heavily on the support of its underlying communication sub-system to transfer multimedia information. The different categories of data traffic required by a DMIS have different transmission requirements. These requirements range from unreliable real-time transmissions (for example, mouse-cursor coordinate data and real-time digitized voice) to reliable bulk data transfers. In this paper, the authors describe the design of a set of multicast communication facilities which fulfil these requirements. Their design is intended to be applied to a wide range of network environments and protocols