Commetrex Corporation Mike Coffee CEO, Commetrex SIP Forum FoIP Task Group “What About Fax?” UC-SIP Trunking Summit FoIP Session 11:00 AM 02/03/11

Commetrex Corporation Timing is everything. In Fax…

3 Fax Relay Packet Network Receiving Fax Transmitting Fax Real-Time Packet-Based Fax Emitting Gateway Receiving Gateway PSTN T.38 T.30

IP-Carrier-Based Voice Voice is generally the default Agree on a codec Enable the media stream Take care of jitter-buffer management Get rid of echo You’re done!

Fax: What’s the Problem? Fax involves a computer-to-computer protocol (T.30) w/ timing requirements Fax involves synchronous modems (not just a different “codec”) For T.38, codec/media must be renegotiated with SIP Timing is everything!

6 Dropped Sample (frequency domain)

The Challenge: Calls don’t begin as a fax call. Can we agree on how the transaction is to proceed: G.711 pass-through fax T.38 Can we switch in time? Can we meet the timing requirements in session setup?

T.38 Deployment Phases: Phase I: Phase II: Phase III:

Intra-Enterprise

And Now…The Carriers!

Service Provider Questions VoIP? CLEC? ILEC? SIP trunking or direct peer? T.38 availability? Routing? G.711 pass-through support required? NAT/firewall solution?

Qualifying a Service Provider Is your service provider experienced? What carriers will be involved? Do they support T.38? What is their footprint? What about NAT? What about support?

Problems: Slow SIP leads to T.38 re-Invite failures G.711 pass-thru PCM clock sync failures V.34-SIP integration is complex

In a Recent Broadcast Test 200 out of 2000 calls had late-arriving T.38 re-Invites.

The Problem

Operational Modes Called GW, V34 fax supported Called GW, V34 fax not supported Calling GW, V34 fax supported Calling GW, V34 fax not supported

Phase II Problems: What’s being done to fix the Phase II problems?

G.711 Clock Sync One second of silence begins here. EVT_IP_RESET

Calling GW w/ V.34

SIP Forum Copyright © 2010 SIP Forum FoIP Task Group

Copyright © 2010 SIP Forum SIP Forum Background Founded in 2000 in Sweden Leading non-profit IP communications industry association Individual, corporate, and academic members

FoIP Task Group Charter SIP networks cannot fully replace analog PSTN unless essential services, such as fax, are provided. Investigate and resolve problems with the deployment of fax services, specifically ITU-T T.38, in SIP networks.

SIP Forum & FoIP Task Group Leadership SIP Forum Leadership: Eric Burger, CTO, NeuStar Marc Robins, Managing Director and President, SIP Forum LLC Richard Shockey, Chairman of the Board Task Group Leadership: Mike Coffee, CEO, Commetrex, Co-Chair Gonzalo Salguiero, Cisco, Co-Chair Max Schroeder, VP, Faxcore, Task Group Whip Copyright © 2010 SIP Forum

Task Group Goal Copyright © 2010 SIP Forum Develop and publish the guidelines (recommended practices) that will reduce the implementation problems that are today hindering IP-based fax deployments in carrier-based applications.

FoIP Task Group Problem Statement Copyright © 2010 SIP Forum Due to increasing carrier support of T.38, barriers to its effective use are moving from the simple case of interop between two T.38 peers within the enterprise to effective SIP- based call setup among multiple network elements in addition to the two T.38 SIP peers, demanding strong cooperation between equipment vendors and carriers.

Results to Date: SIP Forum – Official Fax Over IP Task Group Problem Statement: k,doc_download/gid,372/Itemid,261/ ITU-T SG16-V.153 Recommendations for Consent: k,doc_download/gid,366/Itemid,261/ T.38 SIP-SDP Negotiation Subgroup Problem Statement: http :// / Copyright © 2010 SIP Forum

Next for the Task Group: FoIP must become a robust transport in a global, multinational IP infrastructure.

Fix it Copyright © 2010 SIP Forum But to begin, we must measure it.

SIP Forum FoIP Task Group & The i3 Forum Copyright © 2010 SIP Forum Reliable IP-based real-time fax can only be achieved with effective cooperation between vendors (SIP Forum) and carriers (i3 Forum).

Objectives: Quantify the problem Catalog unsuccessful FoIP calls Statistical analysis of failures Discover relation between successful call rate and delay before re-INVITE to T.38 and the record the route Determine T.38 re-Invite best practices (re: SIP Forum SDP document) Validate proposals with retest

Participants to date: Deutsche Telekom iBasis SFT OTEGLOBE TATA Telkom SA Telekom Italia Sparkle Telecom Poland Telefonica Reach ATT Telenor

Schedule: 1. Installation: Sept-Dec 2. Testing: 1Q11 3. Collection/analysis: Q2 4. Recommendations: Q3 5. Follow-up testing: Q4 6. Final report:Q4/1Q12

Thank you