Faster Music, Movie Downloads

Carnegie Mellon University computer scientist says transferring large data files, such as movies and music, over the Internet could be sped up significantly if peer-to-peer (P2P) file-sharing services were configured to share not only identical files, but also similar files.

David G. Andersen, assistant professor of computer science at Carnegie Mellon, and Michael Kaminsky of Intel Research Pittsburgh have designed such a system, called Similarity-Enhanced Transfer (SET). By identifying relevant chunks of files similar to a desired file, SET greatly increases the number of potential sources for downloads. And boosting the number of sources commonly translates into faster P2P downloads, Andersen explains.

How much SET could speed up downloads varies based on many factors, including the size and popularity of a given file. In some cases, SET might speed transfers by just 5 percent; in others, it might make downloads five times faster.

The researchers, along with graduate student Himabindu Pucha of Purdue University, will present a paper describing SET and release the system code at the 4th Symposium on Networked Systems Design and Implementation, April 11 in Cambridge, Mass.

"This is a technique that I would like people to steal," Andersen said. Though he and colleagues hope to implement SET in a service for sharing software or academic papers, they have no intention of applying it themselves to movie- or music-sharing services. "But it would make P2P transfers faster and more efficient," he added, "and developers should just take the idea and use it in their own systems".........