Distributed Computation of Performance-Aware Webmaps with HTTP Proxies Abstract: Scalable congestion-based routing remains largely an unsolved challenge on todays internet. Companies like Akamai make congestion aware decisions in mapping end users to web servers, but there is little work on how to build a scalable layer-3 solution to dynamic congestion issues. In my project, I will attempt to develop infrastructure and algorithms that could be the basis of such a system. Using a network of HTTP proxies servers like those already common at the edge of the Internet and a combination of passive and unobtrusively active monitoring techniques, it may be possible to generate a real-time picture of congestion conditions on the Internet. Such a web map could supplement BGP info available today to help enable a more intelligent routing system. In my project, I will develop: an enhanced HTTP proxy server, which monitors the TCP connections it proxies to passively determine network performance, and active techniques (similar to traceroute or Stefan Savages TCP probing) for mapping connectivity to origin servers. The proxy will be able to exchange its data with other proxy servers, such that a network of such proxies at the edge of the Internet could maintain a comprehensive picture of Internet performance.