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