P2P Networks

Aug 2003 to Jun 2005

Perhaps the first example of seamless user-contributed content on the internet was Napster, the music sharing software that reached over 25 million users over 3 years before it was shut down in 2002.

Napster paved the way for peer-to-peer file sharing programs like Kazaa and LimeWire as well as user-contributed content sites like YouTube and MySpace.

My own research in peer-to-peer networks arose out of using and observing these networks, and is described by the following 4 themes:

Reputation - One of the biggest problems in P2P Networks today is inauthentic file attacks. It has been suggested that the future of file-sharing P2P Networks depends on the ability to know the reputation of file sources in the network. However, reputation management in open, anonymous, distributed networks presents a number of challenges. EigenTrust is an algorithm that manages reputations in such networks.

Simulation - Testing algorithms on file-sharing P2P networks is often done by simulations, since deploying algorithms on real P2P networks is often impossible. However, many P2P algorithms are sensitive to network and traffic models that are used in simulations. Therefore, to accurately test P2P algorithms, we require a simulator that resembles real-world file-sharing P2P networks as closely as possible. The Query-Cycle Simulator is a file-sharing P2P network simulator that is standardized, extensible, and modeled after measurements in real-world file-sharing P2P networks. We are making the code available so that research groups can test their algorithms on a standardized P2P network simulator

Topologies - We present a peer-level protocol for forming adaptive topologies for file-sharing P2P networks that is based on the idea a peer should directly connect to those peers from which it is most likely to download satisfactory files. We show that the resulting topology is more efficient than standard Gnutella topologies. Futhermore, we show that the resulting topology has the added benefits of increased resistance to certain types of attacks, intrinsic rewards for active peers, and intrinsic punishments for malicious peers and freeriders.

Market Mechanisms - The operation of large-scale competitive P2P systems are threatened by the non-cooperation problem, where peers do not forward queries to potential competitors.

While non-cooperation is not a problem in current P2P free file-sharing systems, it is likely to be a problem in such P2P systems as pay-per-transaction file-sharing systems, P2P auctions, and P2P service discovery systems, where peers are in competition with each other to provide services. Here, we motivate why non-cooperation is likely to be a problem in these types of networks and present an economic protocol to address this problem. This protocol, called the RTR protocol, is based on the buying and selling of the right-to-respond (RTR) to each query in the system.

 

Publications

  • The EigenTrust Algorithm for Reputation Management in P2P Networks- Proceedings of the Twelfth International World Wide Web Conference, May, 2003

    By Sepandar D. Kamvar, Mario T. Schlosser, and Hector Garcia-Molina

  • Simulating a File-Sharing P2P Network- First Workshop on Semantics in P2P and Grid Computing, December, 2002

    By Mario T. Schlosser, Tyson E. Condie, and Sepandar D. Kamvar

  • Incentives for Combatting Freeriding on P2P Networks- Euro-Par 2003, June, 2003

    By Sepandar D. Kamvar, Mario T. Schlosser, and Hector Garcia-Molina

  • Adaptive peer-to-peer topologies- Proceedings of the Fourth International Conference on Peer-to-Peer Computing, 2004

    By Sepandar D. Kamvar, Mario T. Schlosser, and Hector Garcia-Molina

  • Addressing the Non-Cooperation Problem in Competitive P2P Networks- First Workshop on Economics of P2P Systems, June, 2003

    By Beverly Yang, Sepandar D. Kamvar, and Hector Garcia-Molina

  • Non-Cooperation in Competitive P2P Networks- Distributed Computing Systems, 2005

    By Beverly Yang, Tyson E. Condie, Sepander D. Kamvar and Hector Garcia-Molina

Talks

  • The EigenTrust Algorithm for Reputation Management in P2P Networks- Proceedings of the Twelfth International World Wide Web Conference, May, 2003

    Sepandar D. Kamvar

  • Simulating A File-Sharing P2P Network- SemPGrid, 2003

    Sepandar D. Kamvar

Tutorials

  • Query Cycle Simulator

Demos

Code