Issues in improving TCP performance over ATM

We consider the adequacy of TCP control mechanisms for rate- based ATM service classes in general. TCP congestion control and avoidance algorithms are discussed. We study their match to the ATM variable bit rate (VBR) service class. We explain that by using TCP rather than VBR policing we introduce an under-utilization in the network channel capacity. We propose some enhancements and fine tunings to the rate-based classes, present a new TCP window control mechanism and show an improvement in the effective bandwidth used.