Group Communication Using Modular Protocol Stacks

Today's distributed systems consist of many different components, making the efficient management of such systems an extremely difficult task. Group communication should provide a potential solution to make the management process more flexible. It is possible to build a group communication system based on traditional distributed technology such as CORBA (Common Object Request Broker Architecture), but efficiency is poor due to lack of support for multicast and the overhead of building groups in current commercially available products. Multicast is a key part of a future group communication architecture and although reliability is not yet supported there are workarounds which provide a solution. This paper discusses the design and implementation of reliable IP multicast protocols for group communication. One important aspect of this work is the modularisation of the protocol blocks, and the design of a modular protocol, which can be used in conjunction with other similar protocol blocks to build a communication stack for group communications, is described in detail.