A new model with time constraints for conformance testing of communication protocols

In this paper we propose a new model for conformance testing of real-time protocols. First, we point out necessary properties for the model with respect to the following attributes: (1) the description and testing of the time constraints, (2) time-out processing. Although communicating finite state machine (CFSM) and its extension TCFSM are widely accepted as models for communication protocols, these models do not satisfy the necessary conditions, and are not suitable for testing real-time properties. Then we propose a new model CFSM-T which defines a new time constraint [l,u,d] to resolve time difference between clock (logical time) and timer (physical time) and changes the scope of description to processes only. Finally, we apply it to specify the alternating bit protocol. The result shows that the new model CFSM-T would be an effective model of real-time protocols for protocol conformance testing.