Wide Area ATM Network Experiments Using Emulated Traffic Sources
Beng-Ong Lee, Victor S. Frost · 1998
Several wide area network testbeds have been deployed to study the performance of Asynchronous Transfer Mode Networks (ATM). Experiments are being conducted on these testbeds to measure their performance. However, one of the weaknesses of testbed networks is the lack of realistic tra c ows. To experimentally evaluate networks, realistic ows must be generated to emulate the actual tra c. Such source models are needed for network design and to evaluate tra c shaping, routing algorithm, and control mechanisms. Future broadband networks will carry the tra c from commonly used applications, like telnet and ftp. In addition, tra c from video and voice services are expected to be a substantial portion of the network tra c. The exponential-growth of the World Wide Web (WWW) will also have a great impact on the design and the performance of networks. To emulate user tra c on networks, empirically derived tra c models were collected and implemented in NetSpec 3.0, a sophisticated network performance tool. Congestion experiments using these emulated tra c models were designed and conducted. User applications only see packet performance, not ATM performance. As a result, packet delay jitter and packet loss were the performance metrics here. However, the combination of transport level ow control and ATM level tra c shaping is also studied. This allows us to evaluate how lower level