1. Technical Specification for Fax over IPX service Madrid February 2010

2. State of the art of i3F document General prerequisites Detailed technical guidelines Testing recommendations Target technical guidelines Testing recommendations Drafting Group TP R&D TP Study, SIP Forum Ongoing: Slide 3 Survey Valid standards SIP Forum docs. Started: Slide 4 New T.38 version SDP extension Other standards, SIP Forum Problem Statement. Initial list: Slide 5

3. I. General prerequisites 1)Bandwidth calculation - to be prepared by TP R&D 2)VBD requirements – need SDP offer when V.152 is not supported. 3)Redundancy – calculation method for given PL does not exist – test scenario with network QoS degradation is to be prepared (see 4b). 4)QoS parameters a.COS marking – as for voice b.PL measurement question in the survey c.Delay impact on echo suppressors/cancellers – network test to be prepared d.Delay between command and answer – max. RTD measurement vs. terminal timer (network and equipment tests). 5)Gateway resources planning – tbd. on the basis of vendor documentation + test scenario. (general tip: fax relay=G.729) 6)Echo control – echo suppressors/cancellers behaviour (see 4c). 7)Transport – UDPTL recommended.

4. II. Detailed technical guidelines 1)Survey to determine „common denominator” 2)Call setup/Switchover – graphs prepared to be verified. 3)Call flows and SDP O/A – on the basis of SIP forum cooperation. 4)Support of “user=phone” string in T.38 switchover – test scenario 5)T.38 call parameters – first recommendation delivered, to be clarified on the basis of SIP Forum „Problem statement”. 6)Bandwidth extension after t.38 switchover – initial signalling =DTMF, call completed at lower speed.+ SIP Forum „Problem Statement”. 7)Indication for switching to fax upspeed mode into SIP re-INVITE to VBD – vbd=yes (or other SDP parameters?) 8)Encryption – waiting for draft-ietf-avt-dtls-srtp-07.txt for UDPTL 9)Timing and synchronization – problem appears also in TDM ?? 10)ECM – proposal to default disable by gateway 11)SG3 fax guidelines – fallback (SIP Forum).

5. III. Target technical guidelines  Echo control - ITU-T Recommendation V.152 “Amendment 1”, 03/2009  Call Control Protocol - SDSPCapNeg and SDPMediaCapNeg in T.38 version, July 2010, based on draft-ietf-mmusic-sdp-capability-negotiation- 10.txt, SIP Forum SDP document.  T.38 fax call parameters, switchover possibilities, ECM, SG3 fax guidelines - T.38 version, July 2010, SIP Forum call flow document.  Fax only direct T.38 call – SIP Forum SDP document.  Encryption  RFC XXXX on the basis of draft-ietf-avt-dtls-srtp-07.txt for UDPTL  SRTP for RTP stack  ??? for TCP stack.  SIP Forum new „Problem Statement” – identification of new cases.

6. IV. TESTING Equipment tests Testing terminals by PSTN call Time-out for command – answer delay testing T.38 conformity testing for Gateways, ATAs, IAFs Resource capacity testing Network tests Testing VoIP connections IP tests, ping, RTD, jitter, packet loss… Acoustic level & loss between analog terminals (gateway FXS ports) Echo suppression testing (enable delay) Echo cancellation testing (disable delay after ANSam) Interoperability tests Switchover procedures testing Support of “user=phone” string in T.38 switchover. Transmission testing Redundancy level testing for network QoS degradation. Transmission speed registration. Clock synchronization testing for VBD ?? Performance testing