PERFORMANCE COMPARISON OF POLICING MECHANISMS OF ATM NETWORKS THROUGH SIMULATION

Abstract

The Asynchronous Transfer Mode (ATM) is considered as the transport method for Broadband Integrated Services Digital Network (B-ISDN). By using ATM, information flow is carried by cells of fixed size. Cells are transmitted through virtual circuits and are self routed based on their header information. In this way , ATM networks can transmit various types of information in a flexible way. However without appropriate traffic control measures, these high speed networks may easily get congested. To operate in a flexible and efficient way it is necessary to regulate the traffic that flows into the ATM network. Most congestion control schemes used in data networks are not suitable to ATM networks. The best way to control congestion in.ATM networks is by using policing mechanisms. These mechanisms will regulate the traffic that flow into the network and there by reduces congestion. The different policing mechanisms proposed so far are, the "leaky bucket", the jumping window", the "triggered jumping window", and the "exponential weighted moving average" mechanisms. The theory, performance of each mechanism.and the comparison between them are discussed in this dissertation through simulation.