Commetrex Corporation

Mike CoffeeCEO Commetrex

Co-Chair SIP Forum FoIP Task Group

mcoffee@commetrex.com

Phase II FoIP Testing

A Marriage of Necessity

Carriers

Vendors

I3 Forum SIP Forum

http://www.commetrex.com 3

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, intra-enterprise: 1998-2008+

• Phase II, SIP trunking: 2007+

• Phase III, tandem carriers: 2011+

Intra-Enterprise

PSTNEnterprise LAN

EnterpriseGateway

FoIP FaxServer

Fax Terminal

ATA

T.38 Phase I

And Now…Bring on The ITSPs & Carriers!

ILEC

ITSP

IPCarrier

IPCarrier

IPCarrier

Enterprise LAN

FoIP FaxServer

Fax Terminal

ATA

T.38 Phase II

Router

Fax Terminal

Separating the Issues

SIP & T.38

OpenInternet

FoIP FaxServer

FoIP FaxServer

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…It’s About Time

• Computer-to-computer protocol (T.30)

• Synchronous modems

• Media stream, which begins in G.711, wants to be renegotiated and switched to T.38

• Timing is everything!

Phase III: Tandem-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

So…What about testing?

• Many networks are untested for FoIP.

• Many carriers have SBC, proxies, and gateways incorrectly configured.

• Excessive signaling delay remains undiagnosed.

• Routes change frequently

Some Results:

In a recent broadcast test200 out of 2000 calls

had late-arriving T.38 re-Invitesleading to fax failures.

Outbound to ITSP

Remote off hook

T.38 re-Invite

G.711 Audio

Caller

Callee

Point of no return

T.38 re-Invitehere. Bye-bye fax.DIS

So…

Can our industry respond effectively to these problems?

SIP Forum FoIP 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.

The i3 Forum said “YES”

These Carriers said “Yes”!

• Deutsche Telekom

• iBasis

• SFT

• OTEGLOBE

• TATA

• Telkom SA

• WIS

• Telekom Italia Sparkle

• Telecom Poland

• Telefonica

• Reach

• FSB

• Telenor

Phase I Testing Report

INTERNATIONAL INTERCONNECTION FORUM

FOR SERVICES OVER IP(i3 FORUM)

(www.i3forum.org)

Workstream “Technical Aspects”

Testing ReportFax over IP service(September 2011)

I3 Testing Results

Using international-carrier SS7-based routing, call-completion rates were

nominally 50%.

Phase II (Pairs) Testing

• Currently underway

• Testing partners identified

• Dig down for root cause of each problem

Copia-Commetrex Pairs Test

Cbeyond

TeliaxLevel(3)

AT&TTDM

Network

CopiaFax

Server

CommetrexFax

Server

BoarderFunctions

BoarderFunctions

BoarderFunctions

168.75.50.854.55.8.66

192.168.21.3172.16.220.39

63.211.239.146

192.168.22.212

5 U GSX

5 U GSX

5 U 5850

488? 491?

Meanwhile…

And the Next Day?

100% perfect faxes using both SIP trunking

and G.711 over the open Internet.

Intelligent Routing

• User=fax

• ENUM

User=Fax

user-param = "user=" ( "phone" / "ip" / other-user)

RFC 3261, section 25.1, URI Parameters

So, other-user = fax.

ENUM: Tells you where you want to go

• Convert E.164 numbers to DNS lookup

• Returns URI of user’s ENUM record

• Record contains info on all services

• HD voice is driver

• But what about fax?

• Used for IP-only routing

2012 Goal

2012 will be the year the global carriers finally begin the move to

an all-IP network.