Commetrex Corporation

Mike CoffeeCEO, Commetrex

SIP Forum FoIP Task Groupmcoffee@commetrex.com

“FoIP In Carrier Networks”UC-SIP Trunking Summit

FoIP Session11:00 AM 02/03/11

http://www.commetrex.com 2

Fax Relay

PacketNetwork

ReceivingFaxTransmitting

Fax

Real-TimePacket-Based

Fax

Emitting/on-ramp Gateway

Receiving/off-rampGateway

PSTNPSTN

T.38

T.30

T.38 Deployment Phases:

• Phase I: 1998-2008

• Phase II: 2007-2018

Intra-Enterprise

PSTNEnterprise LAN

EnterpriseGateway

FoIP FaxServer

Fax Terminal

ATA

T.38 Phase I

And Now…The Carriers!

ILEC

ITSP

XO

GlobalCrossing

Level(3)

Enterprise LAN

FoIP FaxServer

Fax Terminal

ATA

T.38 Phase II

Router

Fax Terminal

Voice Is Easy!

• 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!

• Call set-up timing not critical.

Timing is everything.

But in Fax…

FoIP…Added Complexity

• Computer-to-computer protocol (T.30) w/ timing requirements

• Synchronous modems(not just a different “codec”) with timing requirements

• For T.38, codec/media must be renegotiated and switched to SIP

• Timing is everything!

Is T.38 the Culprit?

InternetFax Terminal

Fax Terminal

ATA

ATA

http://www.commetrex.com 10

T.38 Interoperability Lab

Carrier-Based Fax

ITSP

ATA

ATA

Fax Terminal

Fax Terminal

ITSP

ILECPSTN

ILECPSTN

IP Carrier

IP Carrier

ILECPSTN

IP Carrier IP Carrier

TDM Carrier

Fax Terminal

Fax Terminal

The Challenge:

• Fax calls begin as voice.

• Negotiation takes time:• G.711 pass-through fax?

• T.38?

• Can we switch to T.38 in time?

In a Recent Broadcast Test

200 out of 2000 callshad late-arriving T.38 re-Invites.

Session Border Controller

Just Kiddin’

SBC

The Slow-SIP Problem

CED

OK T.38

G.711Invite

CNGDCS

Caller’s RTP

Called RTP

DIS

RTP Flows here

Sessionresetshere

Known Issues

• T.38 can be clearer about some parms

• V.34-SIP integration is complex

• Slow SIP leads to T.38 re-Invite failures

Phase II Challenges

What’s being doneabout it?

SIP Forum

Copyright © 2010 SIP Forum

FoIP Task Group

(Founded 9/08)

Copyright © 2010 SIP Forum

www.sipforum.org

• Founded in 2000 in Sweden

• Leading non-profit IP communications industry association

• Individual, corporate, and academic members

SIP Forum & FoIP Task Group Leadership

• SIP Forum Leadership:• 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

FoIP Task Group Charter

Investigate and resolve problems with the deployment of fax services, specifically ITU-T T.38, in SIP networks.

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.

SIP Forum TG Docs

• SIP Forum – Official Fax Over IP Task Group Problem Statement

• Subgroup on T.38/V.34/V.8/V.152 call flows

• ITU-T T.38 SIP/SDP negotiation improvements

Copyright © 2010 SIP Forum

V.34…Added Complexity

• Called GW, V34 fax supported

• Called GW, V34 fax not supported

• Calling GW, V34 fax supported

• Calling GW, V34 fax not supported

T.38/V.34/V.8 Call Flows Doc

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).

What the Industry Needs

Participants to date

• Deutsche Telekom

• iBasis

• SFT

• OTEGLOBE

• TATA

• Telkom SA

• WIS

• Telekom Italia Sparkle

• Telecom Poland

• Telefonica

• Reach

• FSB

• Telenor

Testing Objectives

1. G.711 or T.38?

2. Percentage successful image transfer

3. Time of the T.38 re-Invite

4. Relationship between the re-Invite delay and call success.

5. Image errors and their reasons.

6. Connect times and image-transfer times/speeds.

7. ECM?

8. FEC or Redundancy & depth

9. Call route and success rate correlation

Test Plan

Ready

International Routing

T.38 Problems

Connection

Installation

Status

1 2

Carrier Start dateInst. & Config

Connect to switch

E.164 number delivered

Domestic PSTN to Local Sys.

Local Sys. to domestic PSTN

PSTN Poland to Local Sys.

Local Sys. to PSTN Poland

Poland to Local Sys.

Local Sys. to Poland

DT AG 10 /2010 10/15/2010 OK. OK. OK. Error_4 Error_3

iBasis 10 /2010 12/14/2010 OK. OK. OK.

SFR 06 /2010 12/2/2010 OK. Error_5

OTEGLOBE 06 /2010 11/4/2010 OK. OK. Error_6

TATA 06 /2010 10/18/2010 OK. OK. OK. OK. OK. OK.

Telkom SA 09 /2010 11/3/2010 OK. OK. SIP 406

TI Sparkle 09 /2010 10/8/2010 OK. OK. OK. OK. OK. OK.

TP S.A. 06 /2010 9/1/2010

Telefonica 09 /2010 11/5/2010

Reach 07 /2010 10/20/2010 OK. OK. OK. OK. OK. OK.

PCCW 06 /2010 12/29/2010 OK. Error_8

FT 10 /2010 10/26/2010 OK. OK. OK. OK. OK. OK.

WIS Telecom

3 5 6

Schedule:

• Installation: Oct.-Feb.

• Testing: 1Q11

• Collection/analysis: Q2

• Recommendations: Q3

• Follow-up testing: Q4

• Final report: Q4/1Q12

SIP Forum FoIP Task Group…Conquering FoIP Phase II