1. Congestion control and the P2P value chain
Damon Wischik, UCL
Moez Draief, Imperial

2. 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

3. 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

4. Research question
How should capacity be apportioned between users? How should costs be split?
What is the economy of P2P distribution?

5. 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

6. 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?