Local Coordination for Interpersonal Communication Systems

The decomposition of complex applications into modular units is anacknowledged design principle for creating robust systems and forenabling the flexible re-use of modules in new applicationcontexts. Typically, component frameworks provide mechanisms and rulesfor developing software modules in the scope of a certain programmingparadigm or programming language and a certain computing platform. Forexample, the JavaBeans framework is a component framework for thedevelopment of component-based systems -- in the Java environment.In this thesis, we present a light-weight, platform-independentapproach that views a component-based application as a set of ratherloosely coupled parallel processes that can be distributed on multiplehosts and are coordinated through a protocol. The core of ourframework is the Message Bus (Mbus): an asynchronous, message-orientedcoordination protocol that is based on Internet technologies andprovides group communication between application components.Based on this framework, we have developed a local coordinationarchitecture for decomposed multimedia conferencing applications thatis designed for endpoint and gateway applications. One element of thisarchitecture is an Mbus-based protocol for the coordination of callcontrol components in conferencing applications.