Generating Conformance Test Sequences for Combined Control and Data Flow of Communication Protocols

Using a limited version of Estelle, from which a specification can be represented in terms of an Extended Finite State Machine (EFSM), we develop a technique to generate conformance tests which test both the data flow as well as the control flow. From the EFSM, we generate a Finite State Machine (FSM) with several transitions corresponding to a single transition of the EFSM. Moreover, the input and output parameters are also modified so that an “equivalent” FSM is obtained. The data flow graph (DFG) is constructed directly from the “equivalent” FSM. Test segments are obtained from the data flow graph as well as from the control flow graph and are combined “carefully” to generate an executable test sequence. Test data for the above sequence is chosen using a mutation technique to guarantee detection of specific kinds of faults in the data flow. Control flow is tested in the conventional way.