GLOBAL TRAFFIC CONTROL IN ATM NETWORKS

In this paper, we propose a new framework for global traffic control i n ATM networks which aims to maximize resource utilization and to guar antee the reliable congestion control. To do this, we first propose Gl obal Traffic Control (GTC) mechanism which is based on harmonious coop eration of each traffic control function. GTC measures real bandwidth utilization to compensate inaccuracy of the declared mean cell rate an d ii also monitors cell losses to manage input traffic load when a net work approaches congestion state. We also propose new adaptive connect ion admission control (CAC) algorithms which calculate cell loss perfo rmance of related function blocks in a switch node using only a declar ed peak cell rate and an estimated mean cell rate. We measure only the mean cell rate of the aggregate cell stream in a link to estimate the mean cell rate of each virtual channel connection. We adopt a peak ce ll rate spacer at the User Network Interface (UNI) to compensate a cel l delay variation (CDV). We will also present an approximation techniq ue to estimate a queue length distribution of a general queue. As this technique requires negligible calculation time, it can meet the strin gent requirement on the connection set-up time.