An Intelligent Coherent Approach to Cooperation between TCP and ATM Congestion Control Algorithms—Modeling and Simulation Analysis

Abstract

The combination of transmission control protocol (TCP) and asynchronous transfer mode (ATM) to deliver transport services may incur significant performance penalties due to the interaction of congestion control algorithms of TCP and ATM. In this paper, the authors examine two control categories (explicit window adaptation [EWA] and ACK bucket control [ABC]) and their representative schemes. In particular, they propose the fair intelligent EWA scheme for EWA and the fair intelligent ABC scheme for ABC. The key idea is to combine the feedback information from the receiver, from the ATM network, and from the local information at edge device intelligently to explicitly/implicitly control the TCP rate. The authors present simulation results to show that their schemes can control the buffer occupancy at edge device efficiently and can carry the benefits of ABR end-to-end, resulting in significant improvement in throughput, fairness, packet loss rate, and end-to-end delay for TCP connections. Both schemes are transparent to TCP, requiring no modifications in the ATM networks except at the network edge device. Importantly, they allow TCP to be used with any underlying network, not just ATM, as long as the network is capable of providing explicit feedback information concerning the availability of bandwidth.