ConverStation/2: an extensible and customizable realtime multimedia conferencing system

Multimedia desktop conferencing systems provide several functions, such as connection, a shared chalkboard, a motion video and file transfer. For future extensions, the systems should provide the ability of adding or changing a module without affecting other modules. In addition, a user needs the ability of customizing each module and the ability of selecting modules. The paper describes the extensibility and customizability of the real time multimedia conferencing system called ConverStation/2. The conference kernel of ConverStation/2 is independent from conference tools, and provides an interface to tool modules. A new tool module can be added and work under the conferencing kernel by using the interface. The conferencing kernel provides a common communication interface so that tool modules are unaware of the difference of communication protocols. By developing a communication driver that works under the common communication interface, a new protocol will be easily supported. A chalkboard of ConverStation/2 also has the extensibility. A user can add a new function by writing a program in a script language or by providing the function as a dynamic link library. Moreover, a user can define parameters of each module. For example, the default size and position of the chalkboard window can be easily changed by specifying them in a parameter file.