1. draft-miniero-mediactrl-escs- 00.txt Alessandro Amirante Tobia Castaldi Lorenzo Miniero Simon Pietro Romano (University of Napoli Federico II)

2. University of Napoli - mediactrl WG, 70th IETF meeting, Vancouver, Dec. 3rd 2007 2 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

3. University of Napoli - mediactrl WG, 70th IETF meeting, Vancouver, Dec. 3rd 2007 3 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

4. University of Napoli - mediactrl WG, 70th IETF meeting, Vancouver, Dec. 3rd 2007 4 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? Showed at the demo!

5. IDLE / TERMINATE CONTROL RECEIVED CONTROL PENDING PENDING SENT PENDING CONFIRMED UPDATE SENT UPDATE CONFIRMED WAITING FOR LAST 200 CONTROL / - API 200 / 200 API Error / Error API 202 / 202 API PENDING / REPORT PENDING 200 / - API UPDATE / REPORT UPDATE 200 / - API TERMINATE / REPORT TERMINATE 200 / - API UPDATE / REPORT UPDATE API TERMINATE / REPORT TERMINATE Media Server perspective

6. IDLE / TERMINATE CONTROL SENT PENDING UPDATE 200 / - Error / Error API CONTROL / send CONTROL 202 / - REPORT PENDING / send 200 REPORT UPDATE / send 200 REPORT TERMINATE / send 200 REPORT UPDATE / send 200 202 RECEIVED Application Server perspective

7. University of Napoli - mediactrl WG, 70th IETF meeting, Vancouver, Dec. 3rd 2007 7 User OpenSER University of Napoli Media Server SIP messages (High speed binary connector) Control Channel SIP messages SIP signalling Control Framework signalling RTP data RTP communication Steady-state operation University of Napoli Application Server ( Wesip ) SIP messages

8. University of Napoli - mediactrl WG, 70th IETF meeting, Vancouver, Dec. 3rd 2007 8 User OpenSER University of Napoli Application Server ( Wesip ) University of Napoli Media Server (1)SIP INVITE with COMEDIA SIP signalling Control Framework signalling TCP Control channel setup (2) SIP INVITE with COMEDIA (3) SIP 100 TRYING (4) SIP 100 TRYING (5) 200 OK with COMEDIA (9) TCP connect (Control Channel) (10) SYNCH (Dialog-ID, etc.) (11) 200 OK (6) 200 OK with COMEDIA (7) ACK (8) ACK

9. University of Napoli - mediactrl WG, 70th IETF meeting, Vancouver, Dec. 3rd 2007 9 User OpenSER University of Napoli Media Server (2) SIP INVITE (1) SIP INVITE SIP signalling Control Framework signalling RTP data Third Party Call Control (3PCC) (4) 180 Ringing (3) 180 Ringing (6) INVITE (3PCC) (5) INVITE (3PCC) (7) 100 Trying (8) 100 Trying (9) SDP negotiation with UAC + tags and labels mapping (10) 200 OK (11) 200 OK(12) 200 OK (13) 200 OK (14) ACK (15) ACK(16) ACK (17) ACK RTP media streams flowing University of Napoli Application Server ( Wesip )

10. University of Napoli - mediactrl WG, 70th IETF meeting, Vancouver, Dec. 3rd 2007 10 RTP media streams flowing The UAC is echoed back everything Control channel User OpenSER University of Napoli Media Server SIP signalling Control Framework signalling RTP data Direct Echo example: self connection (1)CONTROL (join UAC to itself) (2) 202 (3) REPORT/PENDING (4) “self-join” UAC (5) 200 OK (6) REPORT/TERMINATE (7) 200 OK University of Napoli Application Server ( Wesip )

11. University of Napoli - mediactrl WG, 70th IETF meeting, Vancouver, Dec. 3rd 2007 11 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…

12. University of Napoli - mediactrl WG, 70th IETF meeting, Vancouver, Dec. 3rd 2007 12 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?

13. University of Napoli - mediactrl WG, 70th IETF meeting, Vancouver, Dec. 3rd 2007 13 Prototype web site The prototype implementation and documentation will be soon available at: –http://mediactrl.sourceforge.nethttp://mediactrl.sourceforge.net Come and visit us ;-) Contacts: spromano@unina.it lorenzo.miniero@unina.it tobia.castaldi@unina.it alessandro.amirante@unina.it