Prefix Caching of Continuous Media Streams in the Internet

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The dramatic growth in the popularity of the Internet, coupled with the increase in user accessspeeds, has led to an increased demand for streaming media services in IP networks. However, theheterogeneous and decentralized nature of the Internet, and the lack of end-to-end mechanisms forquality-of-service guarantees, significantly hampers the effort to provide quality delivery and lowdelay to all clients. The success of multimedia streaming applications hinges on developing newtechniques for providing both low start-up delay and high audio/video quality, without requiringcontrol over the entire path from the multimedia source/server to the end users. We propose anapproach based on active proxy services and prefix caching that has the potential of satisfying theserequirements. Proxy prefix caching is a mechanism whereby the first several seconds of a continuousmedia (CM) object are stored at a proxy server close to a client. The prefix cache allows the proxyto hide latencies introduced by either long end-to-end delays, the need to mask unreliable networkservices, the need to process the stream arriving from the source, or the need to deal with scarceresources between the proxy and clients. In this proposal the researchers outline research investigating several aspects of this mechanism which in-clude:-Design and evaluation of preix caching mechanisms,-Integration of prefix caching with bandwidth smoothing,-Development of effective resource allocation schemes at the proxy, and-Characterization of video sources and Internet traffic to feed into the these investigations. The joint participation of AT&T Research and the University of Massachusetts provides a uniquesynergy that would not otherwise be possible. AT&T provides access to resources in the form ofWorldNet traffic data, which supplies a snapshot of current CM workloads in the Internet, andaccess to video testbed/prototyping platforms that are not readily available in academia. On theother hand, UMass provides a much more long-term perspective than is possible at an industriallab, as well as expertise in the area of active services, bandwidth smoothing, and reliable transportprotocols.