Testing of Communicating Systems presents the latest worldwide results in both the theory and practice of the testing of communicating systems. This volume provides a forum that brings together the substantial volume of research on the testing of communicating systems, ranging from conference testing through interoperability testing to performance and QoS testing. The following topics are discussed in detail: Types of testing; Phases of the testing process; Classes of systems to be tested; and Theory and practice of testing.£/LIST£ This book contains the selected proceedings of the 12th International Workshop on the Testing of Communicating Systems (formerly the International Workshop on Protocol Test Systems), sponsored by the International Federation for Information Processing (IFIP), and held in Budapest, Hungary, in September 1999. The book contains not only interesting research on testing different communication technologies from telecom and datacom systems to distributed systems, but also presents reports on the application of these results in industry. Testing of Communicating Systems will be essential reading for engineers, IT managers and research personnel working in computer science and telecommunications.