Analysis of ATM Adaptation Layers and Service Classes in Providing Quality of Service in a Distributed Systems

Abstract

There has been an increase in the need for multimedia content on the internet deviating from the initial intention of the web as proposed by Tim Berner Lee. This therefore calls for a robust and reliable network infrastructure that will provide an increased in bandwidth, low latency and high availability of the network resources, hence the introduction of the ATM network. An ATM network was invented to support different application with divergent Quality of service (QoS) requirement. To support the QoS requirement of different applications running in the network, the ATM forum has outlined the service class category tailored for such applications. An evaluation of the performance of the distributed network was conducted through a simulation using the riverbed academic edition 14.5 simulator. In each of the experiment, there were two (2) scenarios, in which various multimedia applications deployed were configured to have the AAL2 and AAL5 on each category of the service classes. The study has found out that, some applications do have a high performance when configured on certain classes and AALs. Multimedia applications such as voice, audio and video which requires a tight constraint on delay should be configured on either CBR, nrt VBR and rt VBR for QoS and higher performance. Whiles text-based applications like email, ftp and http have a high performance when configured on UBR and ABR service classes. For database application, it was realized that, they have an optimized system performance and achieving QoS when configured on ABR service class.