SIPfaxEngine: The Right Choice for FoIP Server Platforms

Solving Fax over IP (FoIP) is a complicated problem, caused by three things: the timing requirements of the T.30 protocol over a connection-less packet network, the use of synchronous modems, and carrier/service-provider misbehavior. Our patented Smart FoIP® takes care of the first two issues, and our support solves the third.

But, you ask, what about the other vendors that deliver reliable fax with HTTPS and other techniques. How do they do it without infringing Commetrex’ patent? Over 20 of the most-recognizable names in telecom use Commetrex’ fax technology in their servers, MFPs, and fax machines. And the same terminating-fax technology is used in nearly every FoIP test and measurement product in the industry. Ever wonder why? It is no mystery: Commetrex’ fax technology leads the industry in interoperability, choice, and price.

Ever since we launched the T.38 Interoperability Test Lab in 2002, Commetrex’ T.38 technology has been the interop benchmark. We were able to do that because we invented terminating T.38 in 2000. TerminatingT38, as we call it, allowed us to perform interop testing over the Internet…no planes, trains, or cars. And we did it for no charge. By the end of 2003 we had performed the published tests with what may have been all the industry’s gateway vendors. (There were no servers at the time.) This gave T.38 the launch it needed while if gave us an unequaled reputation for interoperability.

Our licensing business took off, and today most of the servers developed for hosted FoIP applications in the industry are based on Commetrex’ TerminatingT38. We soon added our field-proven modems to produce Multi-Modal Terminating Fax (MMTF), which handled both T.38 and G.711 pass-through fax. Of course, we were also busy licensing our relay technology to gateway OEMs, and today over half the FoIP sessions over carrier networks are supported by Commetrex technology. (But this article is about servers.)

But not everyone needed to make the investment required to develop a proprietary server platform. For those OEMs we had BladeWare, a value-adding HMP telephony platform with our MMTF integrated and ready to deploy, just add your application.

But there are three applications where there is little need for proprietary features: BladeWare FMS (fax media server) is a BladeWare application that implements the fax resource for IMS or IMS-like service networks. All of the end-product functionality is implemented by the OEM’s SIP server, so all of our UC customers use it in hosted UC systems.

The other two applications are quite common: BladeWare Fax-to-Email and BladeWare Email-to-Fax. These apps are specifically designed for the ITSP looking to deploy those two services.

And we are now addressing the value-adding gap between licensing the fax engine (MMTF) and licensing BladeWare by integrating MMTF and SIP call control. If an OEM needs a proprietary platform for whatever reason, and wants to take advantage of Commetrex’ FoIP technology, he would need to develop the balance of the system beyond MMTF. Now, it’s a little known fact that a developer can’t produce a highly interoperable FoIP server by simply following standards since there seems to be an infinite variety of ways the standards (e.g. RFC3261 and T.38) are implemented and integrated since the technology is highly complex and impossible to specify 100%. This means there is no substitute for in-the-field experience other than licensing SIPfaxEngine from Commetrex, since it encapsulates our 14 years of learning what’s out there.

And SIPfaxEngine has more than FoIP and SIP. If also has:
* Smart FoIP®
* In-band DTMF for routing
* RFC2833 for out-of-band tones
* Server registration
* Debug facilities
* Per-call metrics
* RFC6913 for routing
* Reports and logs
* IP V6
* STUN for NAT traversal

FoIP for your server? There’s only one place to go: Commetrex, the industry leader in fax technology development and licensing.

Want to know more? E-mail us at

Timescale Modification

Large countries have regional accents and styles of speaking. Here in the U.S. we in the South think Northerners speak too rapidly; Northerners wish we would ‘just get on with it.’ Timescale modification (TSM), the ability to speed up or slow down the playback of a voice message can help you catch that call-back number left too hastily. The trick is to design the TSM algorithm so that the speaker sounds as she usually does, just speaking slower or faster.

Commetrex’ TSM is now available for license to telecom OEMs that want to add this valuable and differentiating feature to their messaging systems. Check it out at Timescale MST and receive more information call at 770-449-7775 or send an e-mail.

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. Contact us to learn more.