Local coordination for interpersonal communication systems

The decomposition of complex applications into modular units is an acknowledged design principle for creating robust systems and for enabling the flexible re-use of modules in new application contexts. Typically, component frameworks provide mechanisms and rules for developing software modules in the scope of a certain programming paradigm or programming language and a certain computing platform. For example, the JavaBeans framework is a component framework for the development of component-based systems — in the Java environment. In this thesis, we present a light-weight, platform-independent approach that views a component-based application as a set of rather loosely coupled parallel processes that can be distributed on multiple hosts and are coordinated through a protocol. The core of our framework is the Message Bus (Mbus): an asynchronous, message-oriented coordination protocol that is based on Internet technologies and provides group communication between application components. Based on this framework, we have developed a local coordination architecture for decomposed multimedia conferencing applications that is designed for endpoint and gateway applications. One element of this architecture is an Mbus-based protocol for the coordination of call control components in conferencing applications.