On TESTGEN, an environment for protocol test sequence generation, and its application to the FDDI MAC protocol

Test suite generation and selection form important aspects of conformance testing. The test suite generation process is usually tedious and time-consuming. The selection of appropriate test cases with certain fault coverage requires intensive analysis of the protocol. It is difficult to manually generate test suites without errors. The test suite generation process must therefore be automated. This thesis addresses the issues of design and development of the front end of an automatic test suite generation and selection environment named TESTGEN. TESTGEN generates TTCN test suites from the formal specification of protocols. TESTGEN adopts a new test suite generation method based on a combination of the extended transition system (ETS) and ASN.l representation of protocols. The new test generation method integrates the testing of both control part and data part of protocols. The test suites generated by TESTGEN are expected to provide better fault coverage than other existing test generation methods. An Estelle-like intermediate language called Estelle.Y is defined for the ETS-based formal description of protocols in TESTGEN. In order to test the data part, the control part of protocols and the protocol timers more thoroughly, we introduce ASN.l and explicit timer constructs into Estelle.Y. In addition, we design a protocol data structure (PDS) as the internal representations of protocols based on the ETS/ASN.l formalism. A parser is then designed and developed to translate the Estelle.Y/ASN.l specification of protocols into the PDS. We test the parser and verify the correctness of the generated PDS by applying a set of consistency checking functions to PDS. The correctness of PDS can also be verified by printing out the protocol information represented in PDS using a set of printing functions. In order to verify the viability of the TESTGEN environment, as well as to gain experience of conformance testing of high speed network protocols, we specify a specific protocol, the FDDI MAC protocol in Estelle.Y/ASN.l. The formal specification of the FDDI protocol in Estelle.Y and our experience with test sequence generation using TESTGEN are then presented.Science, Faculty ofComputer Science, Department ofGraduat