PERFORMANCE COMPARISONS OF ABT/IT AND DT IN ATM NETWORKS

Abstract

ATM Block Transfer (ABT) is promising for effectively transferring highly bursty data traffic in ATM networks. We develop an approximate analysis for two types of ABT (ABT/DT and ABT/IT) to discuss performance comparisons of ABT/IT and DT. Through numerical examples, we show that ABT/DT is quite sensitive to propagation delays while ABT/IT is not. We next investigate the performance improvement by dynamic bandwidth negotiation, which is applicable to ABT/DT. Bandwidth reduction methods in both of ABT/DT and IT are also examined. Simulation results show that the bandwidth negotiation can improve the performance of ABT/DT, and that in the case of short propagation delays, it outperforms even ABT/IT in terms of throughput. However, it is obtained at the expense of the increased burst transmission times. On the other hand, the bandwidth reduction allows a flexible use of the bandwidth, leading fairly good performance in all parameter regions.