Analysis of dual-bus metropolitan area networks using distributed quantitative stochastic simulation

The Distributed Queue Dual Bus protocol (DQDB) has been adopted by IEEE and by the International Standard Organisation as a metropolitan area network standard. DQDB is also a European Telecommunication Standard. Using distrib uted simulation, this paper analyzes the performance of standard DQDB netwo rks, DQDB networks with slot bandwidth reuse, as well as DQDB networks with slot preuse and reuse. The results suggest that although slot preuse is a conceptual mirror image of slot reuse, the maximum improvement in throughpu t of the networks, the causes of unfairness, and the stations which are unf airly favoured differ depending on the choice of bandwidth single-use, reus e, preuse, or pre-and-reuse. All quantitative performance measures were est imated to a specific precision using automated distributed stochastic simul ation. The design of the DQDB simulators anti practical implications of the results are also discussed.