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Congestion control and the P2P value chain. Damon Wischik , UCL Moez Draief , Imperial. P2P mechanism. P2P algorithms typically choose peers at random They use congestion control, which means they download at a higher speed when the link is uncongested. Problems with P2P.
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Congestion control and the P2P value chain Damon Wischik, UCL MoezDraief, Imperial
P2P mechanism • P2P algorithms typically choose peers at random • They use congestion control, which means they download at a higher speed when the link is uncongested
Problems with P2P it doesn’t make sense to assign bandwidth based only on congestion ? ? ? low-bandwidth peer who has no content peer who can best disseminate the content peer with a good but pricey connection $$ it doesn’t make sense to pick peers at random
Research question • How should capacity be apportioned between users? How should costs be split? • What is the economy of P2P distribution?
The virtual economy of the Internet • TCP, the Internet’s algorithm for congestion control, was invented by Van Jacobson in 1988, to save the Internet from congestion collapse • In 2000, Frank Kelly proved that the TCP algorithm behaves as if there is a virtual economy
The virtual economy of P2P • What “social welfare” do existing P2P algorithms seek to maximize? • What is the economic interpretation of P2P tradeoffs? • should I send to a content-poor peer, or to a well-connected peer? • should I offer to upload, or should I pay to download? • How does the economic interpretation translate into actual algorithms? • How should ISPs use “price signals” in this “virtual economy” to control their networks? • Will the network operate autonomically?