A Tool for Modeling Distributed Protocols

Recent peer to peer protocols have mainly been investigated and tested by discrete-event network simulators, e.g. ns-2. These software products usually model the network topology in great details, thus giving reliable picture about a possible run of the modeled protocol. In most cases they can estimate performance measures like throughput, traffic intensity, probability of failure, etc. These protocols are often analyzed in many ways, non of them are standard. In this paper, we elaborate on a new approach based on cellular automata designed to prove correctness of distributed protocols in some cases. Cellular automata are well known for their complex global behaviors, although they are constructed from simple and similar pieces. We shall demonstrate how standard distributed protocols can be modeled by cellular automata. The correctness of the protocols can also be proved by this technique, or – in some cases – counter-examples may be found. Our approach is supported by a simulator that can help researchers to model their protocols by the proposed method.