Modeling and Simulation of Adaptive Available Bit Rate Voice over Asynchronous Transfer Mode Networks

Abstract

This article presents a modeling and simulation methodology to analyze the performance of voice quality when sent over the available bit rate service in asynchronous transfer mode networks. Sources can modify the rate at which they send traffic to the network based on the feedback carried in the resource management cells. This is achieved by changing the encoding level. As the contention increases to network resources—bandwidth in this case—sources start reducing the rate at which they generate and send traffic. The efficiency of the scheme under different scheduling/drop policies and other operating conditions and environments is evaluated using simulation modeling. Furthermore, sensitivity analysis is applied to different parameters, such as queue size and averaging interval length, to investigate their impact on the performance metrics. Results show that limiting the load to 41% of the link capacity results in an acceptable quality.