Network Performance Evaluation within the Web Browser Sandbox

With the rising popularity of Web-based applications, the Web browser platform is becoming the dominant environment in which users interact with Internet con-tent. We investigate methods of discovering information about network performance characteristics through the use of the Web browser, requiring only minimal user participation (navigating to a Web page). We focus on the analysis of explicit and implicit network operations performed by the browser (JavaScript XMLHTTPRe-quest and HTML DOM object loading) as well as by the Flash plug-in to evaluate network performance characteristics of a connecting client. We analyze the results of a performance study, focusing on the relative differences and similarities between download, upload and round-trip time results obtained in different browsers. We evaluate the accuracy of browser events indicating incoming data, comparing their timing to information obtained from the network layer. We also discuss alternative applications of the developed techniques, including measuring packet reception vari-ability in a simulated streaming protocol. Our results confirm that browser-base