A Viewpoints Approach to Designing Group Based Applications

There is increasing interest in group-based applications for video distribution, multimedia conferencing, publish and subscribe etc. Such applications can use networks efficiently by multicasting (supported traditionally at the network layer, but also now at the application layer). Designing such large-scale distributed systems is a complex task that can be aided by using a viewpoint approach to separate out different concerns, for example to separate object interaction from communications support. This paper extends earlier work on the design of distributed systems that use point-to-point communication to propose a framework within which viewpoints can be used to assist the design of complex applications involving groups and multicasting.