Comparative evaluation of adaptive stochastic and ERICA switch algorithms for ABR traffic management in ATM networks

Abstract

Performances of two explicit rate based congestion control schemes for ABR service in ATM networks: Explicit Rate Indication for Congestion Avoidance (ERICA) and proposed Adaptive Stochastic (AS), are compared under heavy load conditions. Neither of the schemes dictates a particular switch architecture. The requirements tested include: utilization, queuing delay, queuing delay variance and queue size. A simple network topology involves an ATM switching node modeled as a single server queuing system, fed by a number of highly bursty traffic sources. Small and large bursts are used in simulations. The controllable traffic sources' allowed cell rates (ACR) are dynamically shaped by the explicit feedback messages from the switch. The results of a simulation study suggest that AS scheme can provide for higher priority traffic in ATM LANs, shorter queuing delay, queuing delay variance, maximum and mean queue size, while retaining ERICA scheme's utilization.