Novel approach to obtaining stability criteria for individual stations of token ring LANs with asymmetric traffic patterns and/or service strategies

We present a new method for obtaining stability criteria for individual queues of Token Ring LANs. Stability criteria for individual stations are necessary when, as is the case with real LANs, the traffic pattern and/or the service strategy is asymmetric. The method makes no assumption as to the nature of the traffic arrival process or the service strategy. This is particularly useful for the development of new token passing protocols, for which an upper limit to the number of packets a station is allowed to transmit has to be defined. Also, the poisson arrival assumption is relaxed, allowing other arrival processes to be investigated. For instance, we obtain the stability conditions for LANs comprising stations with batch arrival and probabilistic service strategy. Also, a LAN simulator generally requires as input the traffic loads at each station. The stability criteria can be used to validate the set of values corresponding to the loads at the stations, thus reducing the waste resulting from simulations run under unstable loads. This s particularly useful when the behavior of LANs are being studied under heavy loads. We illustrate the usefulness of our approach with a set of results from various arrival process/service strategy combinations.