MODELING AND PERFORMANCE COMPARISON OF POLICING MECHANISMS FOR ATM NETWORKS

ATM networks, as proposed by CCITT as the solution for the future B-ISDN, will provide high flexibility with respect to the varying bandwidth requirements of the different services. This 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 the asynchronous multiplexing principle, results in a need to control the individual cell streams during the entire duration of the cells 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. First, this paper will describe basic design objectives and requirements for such a function. These requirements will serve as a basis for the comparison of some of the mechanisms proposed so far, namely the "leaky bucket", the "jumping window", the "triggered jumping window", the "moving window", and the "exponentially weighted moving average" mechanisms.