Performance analysis of the rotating slot generator scheme

A thorough investigation of the performance of the rotating slot generator (RSG) scheme, based on simulation, is presented. RSG is a medium access control protocol appropriate for high-capacity long-distance metropolitan area networks (MANs). It uses the looped bus architecture of the distributed queue dual bus (DQDB) in which the slot generators for both busses are colocated inside the same station. However in RSG, all the stations, one after the other in a cyclic order, undertake the task of generating and destroying the slots on both busses. In this way the location of the station relative to the slot generator changes dynamically, and its effect on the performance is drastically reduced. The authors investigate the fairness and performance of RSG under symmetric and asymmetric loading, underload and overload conditions, and under the presence of a single or multiple priority classes of traffic. They also compare its performance with different variations of DQDB.