Enhanced available bit rate asynchronous transfer mode TCP/IP networks

An enhancement to Explicit Rate algorithms used in Available Bit Rate (ABR) Asynchronous Transfer Mode (ATM) TCP/IP networks is studied. The enhancement consists of employing additional information from the application layer to the network layer to eliminate the Allowed Cell Rate (ACR) timeout value. Specifically, the ATM Forum has defined a default timeout of 500ms for ABR streams. This timeout is used by the ATM switches to reallocate bandwidth whenever a stream does not send traffic.; The ACR timeout can be eliminated in cases where the traffic behavior is known at the network layer. Since Internet traffic is dominated by HTTP traffic, file size requests are known after a user makes a selection. By passing this information from the application layer to the network layer, the network layer can reallocate bandwidth earlier.; This study examines the Explicit Rate ABR algorithms published by the ATM Forum with the additional use of file size information from the application layer to eliminate the ACR timeout effect. Four major studies are performed using exponential, pareto, trace and synthetic workloads. Statistical performance analysis methods are used to compare the various implementations. It is shown that enhancements to Explicit Rate Indication for Congestion Avoidance (ERICA) and Congestion Avoidance using Proportional Control (CAPC) show improvements in throughput. The enhancements made to Demand Estimate Algorithm (DEA) do not show statistical improvement for throughput in some experiments.; The three principal results of this work are: (1) The sharing of file size between the application and the network layers can improve throughput, (2) The development of a broad range of workloads to test ATM ABR algorithms, (3) The use of web based trace workloads in ATM TCP/IP network simulations.