Applying Automated Model Extraction for Simulation and Verification of Real-Life SDL Specification With Spin

Abstract

Formally defined Specification and Description Language (SDL) is used for the design and specification of complex safety-critical systems. Each change in the specification of the product should be immediately checked formally against the requirements’ specification. This paper presents semi-automated system abstraction, automated model extraction, simulation, and formal verification of real-life complex SDL specification. Sound algorithms implemented in our sdl2pml automated model extraction tool preserve all properties of the SDL system. Sdl2pml includes our model of discrete time, abstraction, and support for all relevant SDL functionality and constructs such as dynamic process creation, rational data types, and communication with more than one process instance. To the best of our knowledge, most of them are not supported by any other known approach. We use our SpinRCP tool for simulation and formal verification of the extracted model with the Spin model checker. We demonstrate the applicability of our approach on ISDN User adaptation protocol from SI3000 Softswitch. The extracted Promela model is the largest one ever processed by Spin. We have shown that Spin simulation and model checking can be applied successfully to such huge models.