A MAN is required to ensure that the information objectives (transfer throughput and delay) are mainrained at a satisfactory level for all customers,in a wide range of conditions us for traffic type and network load.This study aims to provide a performance evaluation of DQDB as a backbone.In this framework a suitable model of the network load is a mix of bursty traffic sources multiplexed in each DQDB station.In heavy load conditions,the delay suffered by each segment in the Local Queue (LQ) at each station is much higherthan that in the Distributed Queue (DQ).This delay mainly burdens stations laying near the ends of the two buses.A performance comparison shows that this behavior is not revealed when the network load is generated by Poisson sources.Therefore this study indicates that DQDB is dramatically sensitive to the type of network load.Finally it suggests that mechanisms which try to balance the bandwidth sharing in overload conditions are not suitable to equalize the segment access delay in normal operating conditions.
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