Page 31 - Asterisk™: The Future of Telephony

tantly, that this price/performance ratio would continue to improve as CPUs continued
to increase in power.
Like so many visionaries, Dixon believed that many others would see this opportunity,
and that he merely had to wait for someone else to create what to him was an obvious
improvement. After a few years, he noticed that not only had no one created these cards,
but it seemed unlikely that anyone was ever going to. At that point it was clear that if
he wanted a revolution, he was going to have to start it himself. And so the Zapata
Telephony Project was born:
Since this concept was so revolutionary, and was certain to make a lot of waves in the
industry, I decided on the Mexican revolutionary motif, and named the technology and
organization after the famous Mexican revolutionary Emiliano Zapata. I decided to call
the card the “tormenta” which, in Spanish, means “storm,” but contextually is usually
used to imply a big storm, like a hurricane or such. §
Perhaps we should be calling ourselves Asteristas. Regardless, we owe Jim Dixon a debt
of thanks, partly for thinking this up and partly for seeing it through, but mostly for
giving the results of his efforts to the open source community. As a result of Jim’s
contribution, Asterisk’s Public Switched Telephone Network (PSTN) engine came to
be.

Massive Change Requires Flexible Technology

The most successful key telephone system in the world has a design limitation that has
survived 15 years of users begging for what appears to be a simple change: when you
determine the number of times your phone will ring before it forwards to voicemail,
you can choose from 2, 3, 4, 6, or 10 ring cycles. Have you any idea how many times
people ask for five rings? Plead as the customers might, the manufacturers of this system
cannot get their head around the idea that this is a problem. That’s the way it works,
they say, and users need to get over it.
Another example from the same system is that the name you program on your set can
‖
only be seven characters in length. Back in the late 1980s, when this particular system
was designed, RAM was very expensive, and storing those seven characters for dozens
of sets represented a huge hardware expense. So what’s the excuse today? None. Are
there any plans to change it? Hardly—the issue is not even officially acknowledged as
a problem.

‡ The term DSP also means Digital Signal Processor, which is a device (usually a chip) that is capable of
interpreting and modifying signals of various sorts. In a voice network, DSPs are primarily responsible for
encoding, decoding, and transcoding audio information. This can require a lot of computational effort.
§ Jim Dixon, “The History of Zapata Telephony and How It Relates to the Asterisk PBX” (http://www.asteriskdocs.org/
modules/tinycontent/index.php?id=10).
‖ If your name is Elizabeth, for example, you will have to figure something else out like elizbth, or elizabe, or
perhaps lizabth. OK, so liz might serve as well, but you get the point.

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