Max-Min Rate Control Algorithm for Available Bit Rate Service in ATM Networks

The deenition of Available Bit Rate (ABR) service has been the focus of the recent activities of the ATM Forum. The Forum has adopted rate-based schemes as the standard for congestion control of ABR services, and has accepted Enhanced Proportional Rate Control Algorithm (EPRCA) as the recommended algorithm for the switch behavior. In this paper, we propose a new binary control algorithm, called Max-Min Rate Control Algorithm (MMRCA), which is fully compatible with the existing ATM standard. The MMRCA scheme uses minimum and maximum rate of all active connections to select which connections should be forced to decrease their rate during congestion, and uses additional congestion detection mechanism to prevent potential congestion by intelligently regulating selected connections. The MMRCA scheme converges to the same equal share for all connections as EPRCA, but achieves faster convergence time. The new scheme also requires smaller buuer sizes at the switches, and higher link utilization than the EPRCA scheme. The MMRCA scheme has signiicantly lower hardware complexity than EPRCA and other existing rate based schemes, since it eliminates the need for oating point division at the switch. The proposed scheme can be extended to implement Explicit Rate schemes with low hardware complexity.