GRAPH MODELING OF COMPUTER COMMUNICATIONS PROTOCOL.

Many of the problems in designing communications protocols, which involve asynchronous parallel processes, are due to the difficulty in recognizing all of the possible orderings in which the significant events can occur and the possible execution sequences which arise from these orderings. The modeling technique examined in this paper is derived from the UCLA Graph Model of Computation and experience with the development of ARPANET. One especially attractive aspect of this modeling technique is the existence of a computer program for testing for the property of proper termination. Proper termination indicates that the process modeled by the graph is in a certain sense well behaved; for example it has no deadlocks. These developments suggest that communications protocols can be modeled by the UCLA Graph Model in a useful and revealing way.