A STUDY OF CONGESTION CONTROL ALGORITHMS FOR ABR TRAFFIC IN ATM NETWORKS

Abstract

The ATM forum has defined a new service class for data applications called Available Bit Rate (ABR) service. While this service does not provide any strict guarantees, it attempts to minimize the cell loss at the expense of delay. Using appropriate distributed flow controls, competing users of this service dynamically share the available bandwidth (left over by other services). A central issue in congestion control for ABR service is the computation of the fair rate for every connection at each switching node in the network. The objective is to determine the fair rate for all the connections in a distributed network under dynamic changes. This has to be done in the absence of centralized knowledge about the network, and without the synchronization of different network components. This dissertation work is aimed at studying various algorithms available to compute the fair share at the ATM switch. Different algorithms appeared in the literature are studied. Also, a simple algorithm is proposed. The performance of these algorithms are compared and evaluated.