Commetrex Owns FoIP Test

If you have used a commercial product that supports FoIP testing, you are likely a user of Commetrex’ T.38 technology, since nearly every OEM in the test-equipment industry bases their FoIP-test products on our Multi-Modal Terminating Fax (MMTF). MMTF is licensed technology that supports T.38 and G.711 pass-through fax send-receive, and it is at the core of their FoIP-test features.

“How did this happen?” you say.

Well, it began with Commetrex’ invention of T.38 termination in 2001…a product we call TerminatingT38. We developed our T.30, the protocol of terminating G3 fax, nearly 20 years ago. Then, we were one of the first two companies in the industry to develop T.38, shipping serial number one in 1999. In 2001 we completed the integration of T.30 and T.38 to create TerminatingT38. Then, we combined TerminatingT38 with our T.30 and fax modems to create MMTF.

In January 2002, we opened the Commetrex T.38 Interop Test Lab, a no-fee open-to-all Internet-based interop-test lab. Within just 18 months nearly every gateway vendor with a fielded product participated. This not only moved T.38 as a standard into much broader interoperability, but it moved our T.38, and, specifically our TerminatingT38 to become the industry benchmark for T.38 interoperability.

As the saying goes: if you build it they will come, and come they did. Our first test-equipment deal came along in 2003. And earlier this year we signed our seventh test-equipment OEM.

If you’d like more info about Commetrex and our technology, send us an email at

Call-Progress Analysis … Some Science, Plenty of Art

Every time we place a call, we instinctively perform call-progress analysis (CPA). We listen for dial tone before dialing, detect ring-back, busy, answer, and so on, without giving it much thought. But duplicating the nearly unfailing precision of human-based CPA in a communications system requires considerable technical accomplishment and even more experience and inventiveness.

Most of you know that CPA is essential for outbound PSTN calls, but it’s also necessary in SIP-based systems, since, once a SIP call is answered, SIP is no longer a help in knowing the nature of the answer; you still need in-band CPA to classify the answer. Is it a voice answer or SIT (system intercept tone)? How about CED, the fax-answer tone? And, in outbound call-center applications, it’s important to know whether voice answer is a person or an answering machine. The difference between a less-than-effective answering-machine detection in CPA and one that achieves better than 90% accuracy, such as Commetrex’ CPA, can mean a savings of over $100,000 per year in a moderate-sized call center.

There is plenty of debate over how to best detect answering machines. Some systems rely on beep tones, but those tones are unreliable and of indeterminate frequency when they do occur. And there is no spectral signature of answering machines. So, what to do? Well, the answer lies in Commetrex’ 10 years-in-the-field CPA.

Our CPA uses frequency analysis to discriminate between voice, which has frequencies throughout the PSTN bandwidth, and CPA tones, which are between 200 and 500 Hertz. But once we determine that there is voice answer, is it a machine? The answer lies in the differences between how we answer a call in person, and the type of message we record for our home systems. Have you ever heard an answer-machine recording just say, “Hello”?
Commetrex’ CPA gives you the features that allow you to differentiate between “Hello” and “Hi, this is Ted and Alice. We’re not in just now, but…” You can license this highly effective CPA, which is used on BladeWare, for your telecom equipment. Many have and you can too.
Want to know more? E-mail us at

Introducing NetGen Communications

Ever heard of NetGen Communications? If you have, it probably had to do with Smart ATA, which was introduced by NetGen at ITEXPO last September. NetGen is a spin out of Commetrex. It’s not a subsidiary; but it has the same ownership as Commetrex. We founded it as a haven for our intellectual property, and it owns the patent rights to Smart FoIP. But now, NetGen has become much more than that.
Commetrex’ market focus is on the telecom OEM, but not every opportunity that Commetrex has looked at fits, so we’ve assigned NetGen the responsibility of producing and marketing end-user products, such as Smart ATA. We are currently expanding headcount at NetGen to support Smart ATA.
For more information on NetGen Communications and Smart ATA, visit the Website at

SIP Forum FoIP Task Group Status

Progress! The FoIP task group has produced a draft of its Phase I test report, which is now in review by the FoIP task groups of the SIP and i3 Forums. You may recall that the FoIP task groups of the SIP Forum, which comprises equipment vendors, and the i3 Forum, which comprises over 37 international carriers, were both established to bring reliable FoIP to carrier networks. And, in June 2010, the two organizations agreed to work together to perform the network testing neither could do alone, but had to be done to reach the goal. To paraphrase the i3 Forum: the global network is moving to IP, and the transition cannot be complete until FoIP in international calls is solid.

In 14 weekly test sessions from December through April 2011, we had amassed a mountain of data from the tests, which consisted of each of the 13 carrier participants doing a fax broadcast to each other. We collected data from the BladeWare-based Copia International fax servers, which had been installed at each carrier location. Of course, our analysis was slowed by summer schedules, but now the test report, which identifies common problems and proposes some solutions, really shows the need for additional testing to investigate the common problems Phase I showed us.
In the second phase of testing, the carriers will test in pairs to facilitate the collection of logs on the sending and receiving sides for each call, allowing us to investigate specific problems identified in the first phase.
Following the Phase II testing (essentially a re-test), the i3 Forum intends to develop an “i3 FoIP Recommendation”, which will include detailed technical guidelines for the carriers. This document should be mirrored on the SIP Forum Website. Our goal is that it will be suitable for submission to the IETF as an informational draft.

To learn more about the task group, email Mike Coffee at

Smart FoIP Components

We’ve said a lot about Smart FoIP being a solution to the “late T.38 re-Invite” problem. But Smart FoIP has two other major functions: eliminating PCM clock-sync problems and T.38 version 3 V.34 integration with SIP. As with late T.38 re-Invites, until Smart FoIP, the industry has been unable to solve the PCM clock-sync problem. And today, there may be no gateways with T.38 V3 with V.34 that actually interoperate with another vendor’s gateway. Smart FoIP is changing that.
Any gateway or server that purports to reach TDM-network fax-transaction success rates in carrier networks must support G.711 pass-through fax, in addition to terminating T.38. The reason is simple, a T.38 re-Invite cannot be guaranteed. Any call may end up G.711, but we all know G.711 success rates are too low for prime time. If you are a service provider, you’ve heard the complaint: “I can send a one-page fax, but multi-page faxes too often do not go through.”

Smart FoIP makes every multi-page fax as reliable as a one-page fax.
And V.34, which transmits a fax page in half the time as V.17, is a different animal. The other fax modems (e.g. V.17, V.29…) have uniquely fax characteristics. But V.34 shares characteristics with V.34 data modems, so a gateway must be able to differentiate between the two and do so in such a way that data modem calls do not receive a T.38 re-Invite and two T.38 version 3-capable gateways do successfully move to T.38 and V.34, and not fall back to V.17.

Smart FoIP implements the logic and that allows two T.38 V3-capable gateways to operate at 33,600 bps when the two endpoint terminals are V.34 capable.
To learn more about Smart FoIP, visit our Website, or call 1-770-449-7775 and press 1.