draft-miniero-mediactrl-escs-00.txt

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draft-miniero-mediactrl-escs-00.txt

• Alessandro Amirante
• Tobia Castaldi
• Lorenzo Miniero
• Simon Pietro Romano
• (University of Napoli Federico II)

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Session Control Protocol (SIP) Control Framework
(ESCS/SCFW) Call Flow Examples

• This document provides a number of Media Server
  Control Framework call flows
• It is meant as a BCP document conceived to help
  the development of the framework specification
  with a practical approach
• All the flow scenarios come from direct
  implementation experience, which can help fix
  potential drawbacks and/or issues emerging in the
  protocol

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A Practical Approach

• The document embraces a practical approach by
  providing
• State Diagrams of the framework protocol (both AS
  and MS perspectives)
• Some implementation-oriented considerations that
  come out of the specification analysis.
• Many real-life scenarios are considered in the
  call flows, and diagrams with different
  perspectives are included

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Call Flows and Diagrams

• Control Channel Establishment
• COMEDIA-based negotiation
• SYNCH framework transaction
• Use Case Scenarios and Examples
• Echo Test
• Direct Echo Test
• Echo Test based on Recording
• Phone Call
• Direct Connection
• Conference-based Approach
• Conferencing
• Simple Bridging
• Rich Conference Scenario
• Coaching Scenario
• Sidebars
• Others?

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CONTROL RECEIVED
API 202 / 202
CONTROL PENDING
IDLE / TERMINATE
API 200 / 200
API Error / Error
API PENDING / REPORT PENDING
200 / -
Media Server perspective
PENDING SENT
WAITING FOR LAST 200
API TERMINATE / REPORT TERMINATE
200 / -
API TERMINATE / REPORT TERMINATE
PENDING CONFIRMED
API UPDATE / REPORT UPDATE
UPDATE CONFIRMED
UPDATE SENT
API UPDATE / REPORT UPDATE
200 / -
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Application Server perspective
202 / -
CONTROL SENT
202 RECEIVED
API CONTROL / send CONTROL
REPORT PENDING / send 200
200 / -
IDLE / TERMINATE
PENDING
Error / Error
REPORT TERMINATE / send 200
UPDATE
REPORT UPDATE / send 200
REPORT TERMINATE / send 200
REPORT UPDATE / send 200
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Steady-state operation
SIP signalling
Control Framework signalling
RTP data
University of Napoli Application Server (Wesip)
OpenSER
SIP messages
SIP messages (High speed binary connector)
SIP messages
Control Channel
User
RTP communication
University of Napoli Media Server
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SIP signalling
Control Framework signalling
TCP
University of Napoli Application Server (Wesip)
OpenSER
Control channel setup
User
University of Napoli Media Server
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SIP signalling
Third Party Call Control (3PCC)
Control Framework signalling
RTP data
University of Napoli Application Server (Wesip)
OpenSER
User
RTP media streams flowing
University of Napoli Media Server
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SIP signalling
Direct Echo example self connection
Control Framework signalling
RTP data
University of Napoli Application Server (Wesip)
OpenSER
User
RTP media streams flowing The UAC is echoed
back everything
University of Napoli Media Server
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Considerations

• Is the 202 message really necessary?
• Always followed by a REPORT(pending)
• Ambiguity between notify/update possible states
  in REPORT messages
• Should notify/update events be possible after a
  terminate?
• Since error messages cannot carry any payload,
  how are package-specific errors notified?
• Should we improperly use either the 200 message
  or the Report/terminate message for this?
• and others, mostly related to each specific
  control package
• WIP

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Discussion

• Is the document of interest to the WG?
• Are the provided scenarios enough? Are they well
  described and analyzed?
• Should security considerations be in the scope of
  this document, or should they just be referenced
  from the specification documents?
• What else is needed and/or needs to be fixed?

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Prototype web site

• The prototype implementation and documentation
  will be soon available at
• http//mediactrl.sourceforge.net
• Come and visit us -)
• Contacts
• spromano_at_unina.it
• lorenzo.miniero_at_unina.it
• tobia.castaldi_at_unina.it
• alessandro.amirante_at_unina.it