Rate Based Flow Control with Bandwidth Information

The ATM Forum has chosen the rate-based approach for flow control of ABR (Available Bit Rate) traffic in ATM. It is based on a reactive approach whereby the transmission rate of ABR sources can be adapted to the available bandwidth at a bottleneck link. The ATM forum has specified the behavior of the source and destination, as well as the manner in which feedback information (on the available bandwidth and on the congestion state of the network) should be conveyed back to the source. The decision on the precise control mechanism, however, has been left to the designer of the switches. We propose in this paper a reactive control scheme that is based only on information on the available bandwidth. We analyze its stability, and then test its performance and fairness by simulations in the presence of other higher priority CBR or VBR traffic.