Symbolic simulation: theory and application to protocol modeling and validation

We present a novel technique called symbolic simulation, and its application to protocol modeling and validation. Whereas simulation produces a trace of the behavior of a system for certain fixed parameter values, symbolic simulation allows one to simulate the behavior of a system for entire ranges of parameter values. This in turn allows verification of certain properties of the system behavior for those ranges of values. This paper lays the theoretical foundation for symbolic simulation, and describes its application to proving safety and liveness properties of protocols. As an example, we have modeled a timer-based connection management protocol and validated one of its safety properties. We conclude that symbolic simulation is a useful means for modeling and validation of complex, real-time communication protocols.