Modelling Enterprise System Protocols and Trace Conformance

Distributed enterprise systems, which are comprised of multiple software systems, typically communicate using application-layer protocols. Being able to independently test each system's conformance to the protocol specification is important to ensure the overall robustness and reliability of the distributed system. While there exists many modelling languages for network layer protocols, very few tools exist for modelling valid message sequences specifically for the application layer. In order to address this issue, we propose a concise formal modelling syntax for application-layer protocols, with clearly defined semantics. A key feature of our protocol model is dynamic extension, which is necessary for the concise modelling of subsidiary concurrent operations. We demonstrate the power of our modelling language by compactly specifying the valid message sequences of two common application-layer protocols. Trace conformance is defined for the model along with a prototype implementation demonstrating the practical utility of our modelling framework.