PowerPoint Presentation Title Subtitle

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XCON WG IETF-71 Meeting Philadelphia, 2008
Centralized Conferencing (XCON) Control Protocol
(CCMP) draft-barnes-xcon-ccmp-04
Authors Mary Barnes (mary.barnes_at_nortel.com)
Chris Boulton (cboulton_at_avaya.com)
Henning Schulzrinne
(hgsxcon_at_cs.columbia.edu)
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Contents

• Introduction
• Changes
• Issue Discussion
• Way Forward
• Comments/Questions

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Introduction

• XCON Conference Framework completed as an XCON WG
  item
• XCON Data model almost done
• Foundation for protocol development is now solid

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Major changes since -03 version

• Added more detail for general description of
  Protocol Operations, including related response
  handling
• Reworked Protocol Operations on conference
  objects section
• Added section on discovery of conference control
  server
• Response handling
• Redefined response codes as tokens (rather than
  digits) for extensibility
• Expanded response section to include details of
  response codes and handling specific to each of
  the types of operations
• Added detailed section for Protocol Parameters.
• Filled out XML schema
• Added IANA registrations

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Document Issues/discussion

• Partial changes to schema
• Currently documented approach requires the entire
  conference object to be sent for changes
• Options
• Add more discrete operations (e.g., addUser vs
  Change)
• Use a protocol for which there is already a
  solution to support partial updates to XML
  schemas (e.g., XCAP)

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Partial update Issue Option 1

• Define more discrete operations (semantics)
• Pros
• Keeps the protocol simpler
• Initially, fairly small subset of operations
• Explicit operations are more efficient
• Easier to avoid non-sensical operations (remove
  half a user)
• Semantic error feedback rather than XML snippets
• Cons
• More complex XML schema for protocol (but quite
  do-able)
• Requires more effort to extend

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Partial update Issue Option 2

• Use an existing XML manipulation protocol
  (syntactic)
• Pros
• May have reusability of stacks for some users
• Might be quicker to completion
• Cons
• May not be ideal fit
• May get some functionality that we dont need
• May need to constrain operations to avoid leaving
  invalid conference descriptions

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Way Forward

• Continue discussion on mailing list
• Solicit additional feedback from WG and potential
  developer community
• Propose to add to XCON charter and move forward.

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• ANY COMMENTS/Questions?

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• Backup
• Document Background
• Protocol comparison chart from IETF-65
  discussions (Updated)

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Document Background

• Henning presented a strawman proposal using a
  simple RPC mechanism (SOAP) for the XCON protocol
  at IETF-63.
• WG chair put forth a challenge to produce
  protocol proposals by year-end 2005 in parallel
  Henning and Mary/Chris produced XML based
  protocol proposals
• Attempt to gather input for protocol semantics
  (verbs/nouns adhoc at IETF-65) was not
  successful
• WG re-vectored a few months later (mid-2006) to
  complete current chartered items, specifically
  focusing on data model and completing framework.
• Early 2007 (IETF-68 timeframe), Mary/Chris
  protocol document combined with Hennings.

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CCP Protocol Overview of options