Automatic test case derivation for communication protocols in an extended FSM model

This paper considers the extended finite-state machine model (EFSM/Pres), w hich has several registers to retain integer values, in addition to the con troller of the finite-state machine. A new method is proposed for automatic ally generating the test sequence for the conformance test, called the E-UI O sequence, from the formal specification of the communication protocol wri tten by that model. In EFSM/Pres, the data type to be handled is restricted to the integer type. The condition for each transition is described by a l ogical expression composed of addition/subtraction and comparison of intege rs. For this class, the input/output sequence composed of the UIO sequence and its precedence sequence is considered. By inputting adequate values to the input variables of the sequence, if the input/output sequences are exec utable regardless of the register values at the start state of the preceden ce sequence, that input/output sequence is called an E-UIO sequence. The ex istence of the state to be recognized is verified by using the E-UIO sequen ce. If the given UIO sequence is. executable, an E-UIO sequence containing the definite input values is always generated automatically. A method to ge nerate automatically a test sequence that verifies the validity of the tran sition is also proposed. As an example, the proposed method is applied to t he OSI session protocol. (C) 1999 Scripta Technica, Electron Comm Jpn Pt 1, 82(10): 50-60, 1999.