Understanding end-to-end performance: testbed and primary results

As the Internet infrastructure evolves to include quality of service (QoS), a lot of work has been done on how to allocate network resources to satisfy the QoS requirements of IP flows. Less attention is being paid to mapping the network QoS specifications, e.g., network delay and loss rate, to the (perceived) end-to-end performance of user applications, e.g., the latency of retrieving a Web page. We study the impact of the network QoS on the perceived end-to-end performance of user applications. We first propose a generic testbed using a combination of simulation and emulation techniques. It can be used to evaluate the end-to-end performance of user applications in different network environments. Next, we use this testbed to study the effect of network QoS metrics on the perceptual quality of various user applications. We focus on estimating the latency of Web retrieval under given packet delay and loss rate and derive an accurate and efficient TCP short connection performance model