PERFORMANCE STUDY OF T-X AND LMT POLICING MECHANISMS FOR ATM NETWORKS

Abstract

ATM network, as proposed by CCITT as the solution for the future BISDN, will provide high flexibility with respect to the varying bandwidth requirements of the different services. They will also support variable bit rates within a connection. The packetized information transfer, without flow control between the user and the network in combination with asynchronous multiplexing principle, results in a need to control the individual cell streams during the entire duration of the calls to ensure an acceptable quality of service for all coexisting calls sharing the same network resources. This kind of control will be provided for by introducing a "policing" or "usage parameter control" function. In this thesis two policing techniques, i.e. T-X Method and LMT Method are discussed. The performance of these methods is discussed and compared using Computer simulation for different input traffic patterns. Performance is compared by computing cell loss probability (CLP) and delay. The effect of Buffer size on the above parameters is also studied. The study made is usefull in analyzing the efficiency of dynamic resource allocation policing techniques for ATM networks.