Simulation study of World Wide Web traffic over the ATM ABR service

Asynchronous transfer-mode (ATM) is the technology chosen for implementing the broadband integrated services digital network. The performance of internet protocols over ATM is an extremely important research area. As web traffic forms a major portion of the Internet traffic, we model WWW servers and clients running over an ATM network using the available bit rate (ABR) service. The WWW servers are modeled using a variant of the SPECweb96 benchmark, while the WWW clients are based on a model proposed. The traffic generated is typically bursty, having active and idle transmission periods. A timeout occurs after a certain idle interval. During idle periods, the underlying TCP congestion windows remain large until the timer expires. This raises the possibility of large queues at the switches, if the source rates ar not controlled by ABR. We study this problem and show that ABR scales well to a large number of bursty TCP sources in the system.