Learning and Testing the Bounded Retransmission Protocol

Using a well-known industrial case study from the verification literature, the bounded retransmission protocol, we show how active learning can be used to establish the correctness of protocol implementation I relative to a given reference implementation R. Using active learning, we learn a model MR of reference implementation R, which serves as input for a model based testing tool that checks conformance of implementation I to MR. In addition, we also explore an alternative approach in which we learn a model MI of implementation I, which is compared to model MR using an equivalence checker. Our work uses a unique combination of software tools for model construction (Uppaal), active learning (LearnLib, Tomte), model-based testing (JTorX, TorXakis) and verification (CADP, MRMC). We show how these tools can be used for learning these models, analyzing the obtained results, and improving the learning performance.