SDL-based feasible test generation for communication protocols

Generation of test cases from a protocol specification for the purposes of testing both control and data flow aspects of a protocol implementation is a challenging problem. We propose an approach for protocols based on extended finite state machine (EFSM) models. Basically, we use the method of H. Ural and A. Williams (see Formal Description Techniques, vol.VI no.C-22, p.335-50, 1994). We extend the method to deal with more than one SDL process. The use of the improved method upgraded with simulation feasibility checking is illustrated by a practical example of test case generation for V5.2 startup procedure that involves the CTRL (control) and LNK (link) protocols with appropriate processes.