Initial experience in implementing multicast facilities in computer supported cooperative work

A description is given of a performance evaluation of multicast communication facilities designed earlier to support computer supported cooperative work (CSCW), (I. Greifetal., 1988). CSCW systems allow a group of individuals working together on a common pool of data as well as making common decisions. These systems often involve dynamic group communications amongst the users in a combination of store-and-forward (e.g., mail) and real-time (e.g., conferencing) modes. A typical communication model for a CSCW environment is presented; it supports the interchange of information among users in both store-and-forward and real-time basis. Multicast facilities are required to support such a one-to-many communication model. The authors propose the design of a set of multicast communication facilities which meet these requirements. These new communication facilities are implemented as both user processes and kernel-level resident code in a UNIX environment. Based on the performance results, they propose modifications to the current implementation to improve the performance. Results obtained from their experiments also serve as guidelines for the implementation of similar communication facilities in future