The research will investigate the appearance of instabilities and performance degradation in computer communication networks; in particular, in CSMA/CD (IEEE 802.3) local area networks. It will be primarily analytic, with a substantial numerical component. The CSMA/CD model will incorporate extensive packet buffering, retransmission counters,and bursty packet arrivals on each network node. Criteria for network stability will be determined, and the first exit time (the mean time to performance degradation in a heavily loaded network) will be computed analytically as a function of network parameters. The research is quite interdisciplinary, including circuit switched networks,and models of local rather global bus contention. The mathematical methods are analytic rather than numerical and allow precise determination of the transient behavior of unstable systems. They are supplemented by numerical computation and comparison with the results of network simulation.
