Dynamic adaptive windows for high speed data networks with multiple paths and propagation delays

Abstract

The optimal design of windows for virtual circuits has been studied for high-speed, wide-area data networks in an asymptotic framework in which the delay-bandwidth product is the large parameter. The authors (1990) previously proposed and evaluated a new class of algorithms for dynamically adapting windows in single path, multi-hop networks. Here they develop algorithms for networks having multiple paths with different propagation delays. The source of each virtual circuit (VC) measures the round-trip response time of its packets and uses these measurements to adjust its window with the goal of satisfying certain asymptotic identities that have been proven to hold in stationary asymptotically optimal designs. Also evaluated is the performance of the new adaptive algorithms in realistic, nonstationary conditions by simulations of networks with data rates of 45 Mb/s and propagation delays of up to 47 ms. The simulation results generally confirm that the realizations of the adaptive algorithms give stable, efficient performance and are close to theoretical expectations.