Testing of Communicating Systems presents the latest world-wide results in both theory and practice. This volume provides a forum in which the substantial volume of research on the testing of communicating systems, spanning from conformance testing through interoperability testing, to performance and QoS testing, is brought together. 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. This book contains the selected proceedings of the 11th 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 Tomsk, Russia, in August/September 1998. Testing of Communicating Systems will be essential reading for engineers, IT managers and research personnel working in computer sciences and telecommunications.