Book excerpt: This book constitutes the refereed proceedings of the Third International COST 237 Workshop, held in Barcelona, Spain, in November 1996. The 15 revised full papers presented in the volume were carefully selected from a total of 34 submissions by COST project participants as well as from outside. The papers are organized in sections on multipeer and group communication, quality of service, applications and teleservices, multimedia protocols and platforms, and performance studies.