Performance of alternative MAN architectures for high-speed data applications

The authors analyze the performance of alternative metropolitan area network architectures for traditional data networking and for emerging distributed client/server computing applications. A simple traffic model contains the essential features of distributed computing applications. Delay performance on the MAN is examined for two architectures: networking based on variable-size datagrams, and networking based on asynchronous transfer mode protocols that use short, fixed-length cells. It is shown that the traffic characteristic of client/server computing-bimodal message-length distributions and bursty, clustered arrivals-can have significant effects on the delay performance of MANs. In particular, the presence of large and variable-size datagrams leads to large delays and variabilities in delay in connectionless networks as the length of network connections increases. Networks that use small cells in the style of ATM provide superior end-to-end delay performance and therefore provide a superior architecture for MANs designed to carry a diverse traffic mix