Multi-Party Multimedia Applications

Winter 1997 Introduction CoMMware is a communication middleware system. Using a common overall architecture, distinct versions have been built in Bell Labs and in Lucent Technologies’ Business Communications Systems Division. This paper describes the Bell Labs version. CoMMware is a collection of software modules that helps developers write multi-party multimedia applications, such as real-time conference programs, distance learning tools, and distributed games. As Figure 1 illustrates, this collection of software components may be characterized as a conceptual layer, situated between higher-level application programs and underlying computation and communication systems. Middleware, which hides details of lower-level operating systems and networks from the application developer, is described by and made available through its application program interfaces. Thus, middleware creates a stable programming base for building applications that can execute on various computer systems and communication networks. While the more familiar and fundamental middleware provides distributed programming tools, communication middleware also provides quality-ofservice communication support. Applications can use this program base for an important set of core functions including multi-party session management and multimedia connection management. Furthermore, these core functions are available on several operating system and network platforms. Therefore, an application—for example, an audio-video conferencing system—could be built using CoMMware to execute on both local area network (LAN) and integrated services digital network (ISDN) platforms. CoMMware helps people build distributed programs and encourages construction of applications through composition of program modules. Its program development environment includes a definition lan♦ Communication Middleware for Multi-Party Multimedia Applications J. Robert Ensor and Sudhir R. Ahuja