Compositional Analysis of Mobile Network Protocols

A compositional framework is proposed for modelling network protocols with symbolic transition graphs. The main advantages of the framework are that it can address dynamic network topologies without requiring additional mobility facilities; and it can work out system models that preserve deadlock freedom, namely the deadlock freedom of a system model depends only on the deadlock freedom of its each task component. Case studies with Mobile IPv4 and IPv6 illustrate the effectiveness of the modelling framework. The model checking experiments show that the framework can extend the capability of the model checker to deal with more complicated system models than can be dealt with by direct model checking. Moreover, some infrangibilities of Mobile IPv6 are disclosed in the sense that it can not maintain the binding coherency all the time, which may result in unreachable or unstable routes.