Commetrex Corporation
“FoIP In Carrier Networks”
UC-SIP Trunking Summit
FoIP Session
11:00 AM 02/03/11
Mike Coffee
CEO, Commetrex
SIP Forum FoIP Task Group
mcoffee@commetrex.com
Fax Relay
T.38
Emitting/on-ramp
Gateway
PSTN
Transmitting
Fax
Receiving/off-ramp
Gateway
Packet
Network
Real-Time
Packet-Based
Fax
PSTN
Receiving
Fax
T.30
http://www.commetrex.com
2
T.38 Deployment Phases:
• Phase I: 1998-2008
• Phase II: 2007-2018
Intra-Enterprise
Fax Terminal
T.38
Phase I
ATA
PSTN
Enterprise LAN
Enterprise
Gateway
FoIP Fax
Server
And Now…The Carriers!
T.38
Phase II
XO
Fax Terminal
Level(3)
ITSP
ATA
Global
Crossing
Enterprise LAN
ILEC
Router
FoIP Fax
Server
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.
But in Fax…
Timing is everything.
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?
ATA
Fax Terminal
Internet
ATA
Fax Terminal
T.38 Interoperability Lab
http://www.commetrex.com
10
Carrier-Based Fax
Fax Terminal
ILEC
PSTN
IP Carrier
IP Carrier
ATA
ITSP
IP Carrier
TDM Carrier
Fax Terminal
ILEC
PSTN
ILEC
PSTN
ITSP
IP Carrier
Fax Terminal
Fax Terminal
ATA
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 calls
had late-arriving T.38 re-Invites.
Session Border Controller
Just Kiddin’
SBC
The Slow-SIP Problem
CNG
DCS
Caller’s RTP
CED
DIS
Called RTP
G.711
Invite
OK
RTP
Flows
here
T.38
Session
resets
here
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 done
about it?
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
Copyright © 2010 SIP Forum
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
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.
Copyright © 2010 SIP Forum
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
T.38/V.34/V.8 Call Flows Doc
• Called GW, V34 fax supported
• Called GW, V34 fax not supported
• Calling GW, V34 fax supported
• Calling GW, V34 fax not supported
SIP Forum FoIP Task Group & The i3
Forum
Reliable IP-based real-time fax
can only be achieved with
effective cooperation between
vendors (SIP Forum) and carriers
(i3 Forum).
Copyright © 2010 SIP 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.
2.
3.
4.
5.
6.
7.
8.
9.
G.711 or T.38?
Percentage successful image transfer
Time of the T.38 re-Invite
Relationship between the re-Invite delay and call
success.
Image errors and their reasons.
Connect times and image-transfer times/speeds.
ECM?
FEC or Redundancy & depth
Call route and success rate correlation
Test Plan
Ready
International
Routing
T.38
Problems
Connection
Installation
Status
1
2
5
Local
Connec E.164
Domestic
Sys. to
t to
number PSTN to
domestic
switch delivered Local Sys.
PSTN
Carrier
Inst. &
Start date
Config
DT AG
10 /2010
10/15/2010
OK.
iBasis
10 /2010
12/14/2010
OK.
SFR
06 /2010
12/2/2010
OK.
OTEGLOBE
06 /2010
11/4/2010
OK.
TATA
06 /2010
10/18/2010
OK.
Telkom SA
09 /2010
11/3/2010
OK.
TI Sparkle
09 /2010
10/8/2010
OK.
TP S.A.
06 /2010
9/1/2010
Telefonica
09 /2010
11/5/2010
Reach
07 /2010
10/20/2010
PCCW
06 /2010
FT
10 /2010
WIS Telecom
3
OK.
OK.
Error_4
OK.
OK.
PSTN
Poland to
Local
Sys.
6
Local
Sys. to
PSTN
Poland
Error_3
Error_5
OK.
Error_6
OK.
OK.
OK.
SIP 406
OK.
OK.
OK.
OK.
12/29/2010
OK.
Error_8
10/26/2010
OK.
OK.
OK.
OK.
OK.
OK.
OK.
OK.
OK.
OK.
OK.
OK.
OK.
OK.
OK.
OK.
Poland Local
to Local Sys. to
Sys.
Poland
Schedule:
•
•
•
•
•
•
Installation:
Testing:
Collection/analysis:
Recommendations:
Follow-up testing:
Final report:
Oct.-Feb.
1Q11
Q2
Q3
Q4
Q4/1Q12
SIP Forum FoIP Task Group…
Conquering FoIP Phase II