AN APPROXIMATE PERFORMANCE FAIRNESS ANALYSIS OF THE P(I)-PERSISTENT PROTOCOL WITH DESTINATION RELEASE

Sufficient conditions are derived for achieving the two most important fairness criteria in the design of access protocols for high-speed me tropolitan area networks (MAN), the delay and throughput fairness crit eria. A probabilistic scheduling scheme, known as the p(i)-persistent protocol is considered, which has been shown to be suitable for applic ations requiring large bandwidth over long repeater-free distances and also amenable to an approximate analytical performance evaluation. It is found that the throughput fairness criterion is easier to achieve than its delay counterpart. The delay fairness, when achieved, induces approximate throughput fairness. The current practice in the field of protocol design for unidirectional bus MAN's appears to focus almost exclusively on the throughput fairness. For example, in the DQDB proto col, although a bandwidth balancing function exists, balancing delay p erformance has never been dealt with.