Part 1 Invited paper I: formal methods for conformance testing - results and perspectives, A.R. Cavalli et al; test generation and coverage - fault coverage of UIO-based methods for protocol tesing, H. Motteler et al; executable testers, M. Phalippou; generating tests for control portion of SDL specifications, G. Luo et al; test suite generation for application layer protocols from formal specifications in Estelle, O. Henniger et al; tutorial - a framework for the design for testability of communication protocols, S.T. Vuong et al; testability and architecture - on evaluation of testability of protocol structures, A. Petrenko et al; ATM broadband network testing using the ferry principle, M.F. Witteman and R.C. van Wuijtswinkel; generating synchronizable test sequences based on finite state machine with distributed ports, G. Luo et al. Part 2 Invited paper II: conformance relations and test derivation, A. Petrenko et al; industrial reports and tools - experiences with computer aided test case generation, A. Ek et al; protocol test case vizualization, P. Kalyanasundaram and P.D. Amer; the UBC protocol testing environment, S.T. Chanson et al; experience with Octopus automated TTCN translation tools applied to GSM/SS7, A. Ahtiainen et al. Part 3 Invited paper III: a formal approach to conformance testing, J. Tretmans; test generation - test derivation from LOTOS using structure information, A. Ulrich and H. Konig. Part 4 Invited paper IV: the refusal graph - a tradeoff between verification and test, K. Drira; interoperability and nondeterminism - interoperability testing - basis for the acceptance of communication systems, G. Vermeer and H. Blik; deriving coordinated testers for interoperability, R. Castanet and O. Kone; adaptive testing of non-deterministic communication protocols, M. Ghriga and P.G. Frankl; nondeterministic state machines in protocol conformance testing, A. Petrenko et al.