For those of you working with Fax of IP, an interesting book called "Fax, Modem, and Text for IP Telephony" was recently published by Cisco Press. This book covers both T30 and T38 basics, as well as much more. It has very positive reviews on Amazon. Check it out! Shifting gears... Need to...
In the late '70s, T.30 was created to make fax machines something they had never been before, interoperable. But many of their manufacturers wanted to go outside of T.30 and continue to use some of their non-standard tricks and abilities. The integrated circuit had begun to make good on its promise...
Now that the V.34 compatibility battle is finally being won, a new problem has surfaced. How do two fax terminals that were attempting to use V.34 mutually decide to abandon it, fall back to V.17 and complete sending their pages? When the "Super G3" V.34 fax modulation was initially released...
There is an article of faith among analog electronics engineers that, if you have to send a signal through difficult conditions, pumping up the power is a good, time honored approach to doing so. But, what about distortion? Somewhere power boosts have to encounter diminishing returns of signal quality...
The dichotomy of fax protocol conformance versus interoperability becomes most pointed when it is necessary to gauge the performance of a fax terminal. A Quality of Service (QoS) standard is simply a necessity for this type of evaluation. The ITU undertook the task of creating such a standard in 1993...
How can data files that monitor the same test call but come from disconnected sources be directly compared with each other? In the Post Mortem Analysis of T.30 and T.38 Traffic posting, I pointed out that QualityLogic's DataProbe T30-T38 Analyzer has the ability to import fax call data from .wav...
Facsimile traffic has followed voice traffic in its migration to the Internet. Historically, the T.30 protocol has been used to transmit facsimile messages over the traditional PSTN network. Because T.30 contained a variety of timing constraints that could not be guaranteed with packet traffic routing...