The What, Why, and How of Interoperability Testing

Software systems have had at least some need to share data and status (interoperate) with each other for over half a century.
For humans, interoperability has typically been a matter of clarity and complete content in written and spoken communications. As situational stress mounts, managing …

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Top 3 Fax over IP Challenges and How to Solve Them

Facsimile —commonly known as fax— came to the fore in the 1970’s when consumer electronics were boosted dramatically by the creation of inexpensive integrated circuits. The opportunity to sell inexpensive fax terminals brought the manufacturers of proprietary fax devices together to find a common protocol …

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How’s the Quality of Your Quality?

In the conversation about quality, one aspect that is too often overlooked is the quality of the quality effort itself. How does QA know that it is doing a good job of managing its own efforts?
Assessment of software quality commonly relies on quality assurance …

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Fax Transmission Power — More Is Not Always Better

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 …

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What’s New in FaxLab 9?

FaxLab 9, the latest version of QualityLogic’s fax interoperability test tool, adds 20 new fax and multi-function peripheral profiles. Network equipment providers and carriers use FaxLab to identify message degradation caused by the network transport, as well as fax protocol violations in gateways. FaxLab is …

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What Is Non-Standard Facilities (NSF)…and Why Should I Care?

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 …

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V.34 to V.17 Can Be a Hard Fall

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 …

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Post Mortem Analysis of T.30 and T.38 Traffic

Fax 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 …

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Comparing Fax Call Data From Different Sources

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 …

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How Version 3 of T.38 Increased Internet Fax Speed

Economic conditions being what they are, the Fax over IP (FoIP) user community is looking for an edge. V.34 ‘Super G3′ fax, covered by version 3 of T.38, makes Internet fax transmissions really move, saving money and bandwidth. The original version 0 of T.38 was …

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ITU E.450 Figure Of Merit – Fax Terminal Performance

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 …

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