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P2P

P2P. Cullen Jennings fluffy@cisco.com. Out of scope. Mechanisms File Sharing Fluffy’s Hair XCAP. P2P What. Media relays Storing buddy list / address book Rendezvous Storing voice mail Anonymization of media Small PBX system. Properties Interesting. No central server

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P2P

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  1. P2P Cullen Jennings fluffy@cisco.com

  2. Out of scope • Mechanisms • File Sharing • Fluffy’s Hair • XCAP

  3. P2P What • Media relays • Storing buddy list / address book • Rendezvous • Storing voice mail • Anonymization of media • Small PBX system

  4. Properties Interesting • No central server • No infrastructure • Reduced Op/Ex • Anonymous communications • Scalability • Reliability

  5. Types of P2P Systems • Type D: Use DNS but client to client • normal sip call directly between UA • unix talk • Type C: Hybrid supernode + clients • normal sip with proxy • napster • Type B: Occasional DNS • use DNS to get into system but after than just use P2P mechanism • gnutella • Type A: no reliance on central servers (no DNS) • adhoc rendezvous based IM in ichat

  6. Security Properties • Hard to stop your name form being stolen • Hard to guarantee no duplicate names • No single server can take you down • DOS? • Admin Fat Fingers config • RIAA shuts you down • Anonymization with no server to subpoena

  7. Trust Model of Internet • Trust of names based on DNS and delegation of hierarchy • CA names are an example of this • SSH, email, PGP use names • Names connect the internet to humans • Make assumptions about crypto stuff • Largely assumes secure/not secure (binary) • Stretched our mind to do leap of faith system

  8. Trust Models of P2P • Statistical likelihood prediction of security • Assumptions very dubious based on general mix of existing good/evil in the network • May not be able to generate unique names

  9. Properties of Names & Rings • Would be nice to: • Control what ring you join • Be able to merge rings without name changing • Be able to move back and forth between traditional DNS SIP AOR and ring name • TradSip can reach ring dwellers

  10. Supernode Characteristics • How to find ones that are: • stable, stay up persistent • can store stuff • topologically the right place

  11. Rings and Rings That Bind Them • Simple systems seem to start with single ring • More complex systems seem to put super nodes at one level in ring and run some sub

  12. IETF Drafts • David A. Bryan and Cullen Jennings : A P2P Approach to SIP Registration draft • draft-bryan-sipping-p2p-00 • Alan Johnston : SIP, P2P and Internet Communications • draft-johnston-sipping-p2p-ipcom-00 • P. Matthews and B. Poustchi : Industrial-Strength P2P SIP • draft-matthews-sipping-p2p-industrial-strength-00

  13. Web Pages • www.p2psip.org • Lots of links to P2P SIP resources • Link to the W&M Technical Report: Bryan and Lowekamp, SOSIMPLE: A SIP/SIMPLE Based P2P VoIP and IM System (technical report, older than our draft!) • www1.cs.columbia.edu/~kns10/research/p2p-sip • several technical reports • Columbia Technical Report: Singh and Schulzrinne, Peer-to-Peer Internet Telephony using SIP (technical report)

  14. References • Stoica et al., Chord: A scalable peer-to-peer lookup service for internet applications • Rowstron and Druschel, Pastry: Scalable, Decentralized Object Location, and Routing for Large-Scale Peer-to-Peer Systems • Guha, Takeda and Francis, NUTSS: A SIP-based Approach to UDP and TCP Network Connectivity • Castro et al., Secure Routing for Structured Peer-to-Peer Overlay Networks • Dabek et al., Designing a DHT for Low Latency and High Throughput

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