The Effect of Bursty Lengths on DQDB Networks

The distributed queue dual bus network is a LAN/MAN protocol proposed by the IEEE 802.6 committee. It can integrate isochronous and nonisochronous services. Due to its medium access control protocol, the network has the unfairness of access for bursty traffic. This paper explores the effect of bursty lengths on the unfairness. In the simulations of the paper, the average delays of distributed and local queues of nodes are calculated for exhibiting the variation of unfairness corresponding to the alteration in the number of cells of bursty messages. The simulation shows that the unfairness is obviously affected by bursty lengths. As the number of cells increases, the unfairness of the delay of distributed queues will be more moderate. But the unfairness of the delay of local queues will become more severe. On the other hand, the throughput of the network is irrelevant to the bursty length