INFLUENCE OF THE BWB MECHANISM ON SOME PERFORMANCE FIGURES OF A DQDB SUBNETWORK

This paper is based on a methodology which evaluates the parameters of a discrete-time first-order Markov process that models the slot-occup ancy-pattern process on the forward bus of a DQDB network (i.e., the p attern of the slots (busy vs. empty) traveling on that bus). The metho dology is an extension of the one proposed in [9] and, although applie d in this paper to analyze DQDB with the Bandwidth Balancing mechanism (BWB) and Poisson arrival processes, it can be used for dual-bus netw orks whenever the arrival process to each node is a superposition of c ompound Poisson processes. The results show that the interdependence b etween slots is significant and, in some configurations, this interdep endence is affected significantly by the BWB mechanism. To analyze how the BWB mechanism influences certain delay performance figures, we in vestigated the performance of a gateway that concentrates several DQDB subnetworks into a slotted trunk and we determined the access delay o f the rightmost DQDB node. The accuracy of our results is verified via a simulative analysis.