Context independent unique sequences generation for protocol testing

A number of test sequence generation methods proposed for protocols represented as extended finite state machines (EFSMs) use state identification sequences for checking the states. However, neither a formal definition nor a method of computation of these sequences for an EFSM state is known. We define a new type of state identification sequence, called context independent unique sequence (CIUS) and present an algorithm for computing it. A unified method based on CIUSes is developed for automatically generating executable test cases for both control flow and data flow aspects of an EFSM. In control flow testing, CIUSes are very useful in confirming the tail state of the transitions. In data flow testing, CIUSes improve the observability of the test cases for the def-use associations of different variables used in the EFSM. Unlike general state identification sequences, the use of CIUSes does not increase the complexity of the already intractable feasibility problem in the test case generation