draft-bryan-sipping-p2p

1
draft-bryan-sipping-p2p

• David Bryan
• IETF 63, Paris
• August 3, 2005

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Current State of Draft

• Draft revised July 15
• This is still a straw man, proposal to encourage
  discussion and document our research
• Most important changes were revisions to the
  explanatory sections
• Attempted to clarify some of the sections that
  were confusing
• Lots of mechanism in the draft, but explanation
  text is most important
• Syntax changes include changing how URIs are
  handled (move toward URI parameters) and
  modifying the headers defined in draft to
  correspond
• Still much to be done
• Identify the limitations, pro-cons of different
  approaches
• Identity problem

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Basic Overview

• Essentially, proposal replaces centralized
  registrar with cooperating nodes
• Defines a DHT based approach, loosely based on
  Chord
• Changed to be iterative, rather than recursive
• Hosting node replies on its own behalf, not
  successors
• SIP REGISTER overloaded to allow not only user
  registrations, but node registrations (DHT
  operations)
• Uses buddy list/phone book to augment search
• Several uses we are interested in
• Small organizations
• Emergency scenarios
• Large scale communication

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Implementation

• Have working prototype supporting our current
  draft, based on reSIProcate stack
• Using implementation to verify the concepts in
  the draft work, explore different routing
  algorithms
• Lots of alternatives, Communications systems are
  fundamentally different from file sharing
• Less resources stored per user
• Latency more important
• Guaranteed query completion/accuracy

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Work to be done

• SIP w/some DHT for lookup or implement DHT using
  SIP? (we do later)
• Media/NAT issues
• Distributed identity
• Security
• Prevent spoofing, prevent squatting IDs, dont
  enable illegal file sharing or DOS attacks
• Routing algorithms designed for P2P
  communications
• Supernodes, ICE, Turn servers?
• Likely first step is to figure out all the places
  that P2P may be useful for SIP and create a draft
  defining the problem space

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References

• draft-bryan-sipping-p2p-01
• D. A. Bryan, B. B. Lowekamp and C. Jennings,
  SOSIMPLE Towards a Serverless, Standards-based,
  P2P Communication System, AAA-IDEA, June 2005
• Stoica et al., Chord A Scalable Peer-to-Peer
  Lookup Protocol for Internet Applications,
  IEEE/ACM Transactions on Networking (to appear)
• (Dont use the algorithms from SIGCOMM paper by
  same authors with same title it contains some
  algorithmic errors)
• I maintain a list of references at
• http//www.p2psip.org
• Contact me via email
• bryan at ethernot dot org