Data flow control in ATM networks: an evaluation of ER and BCA

Data traffic in modern telecommunications systems is loss-sensitive, delay-insensitive, and highly bursty. Most data applications cannot predict their own traffic parameters, but require low cell loss rates. These features make traffic management for data traffic complex. In ATM networks, where multiple types of applications co-exist, it becomes even more difficult. Many models have been proposed for the flow control of data traffic over ATM networks. Among them the explicit rate (ER) mechanism proposed for the available bit rate (ABR) service is the principal method. The ER and other proposed mechanisms are found to suffer in some regard. These mechanisms also need many buffers in the intermediate switches and thus increase the hardware costs. Flow control based on bandwidth contracting (BCA), can achieve higher bandwidth throughputs at lower hardware costs. In this paper, we evaluate ER and BCA mechanisms in LAN and WAN environments for bursty data traffic. This study focuses on the use of short-term bandwidth contracts for the reliable transport of bursty data.