Changes

==The History of App_Rpt==

==The History of App_Rpt==

By Jim Dixon WB6NIL<br/>

By Jim Dixon WB6NIL<br />

<p>Once upon a time, there was [http://www.asterisk.org Asterisk PBX]. I was heavily involved in its initial practical implementation (<font size="-1">if interested, see link below <i>(The History of the Zapata Telephony Project as it relates to the Asterisk PBX</i></font>).</p>

<p>Once upon a time, there was [http://www.asterisk.org Asterisk PBX]. I was heavily involved in its initial practical implementation <font size="-1">if interested, see below <i>(Zapata Telephony Project as it relates to the Asterisk PBX</i></font>).</p>

<p>From its very onset, I saw that Asterisk was not only a good telephony switch, but also makes a good application implementation platform for virtually any telecommunication application that requires use of many of the things that Asterisk provides.</p>

<p>From its very onset, I saw that Asterisk was not only a good telephony switch, but also makes a good application implementation platform for virtually any telecommunication application that requires use of many of the things that Asterisk provides.</p>

<p>App_Rpt was started, not only to demonsrtate this feature of Asterisk, but to essentially provide an outlet of nearly 30 years of experience and frustration with repeater and remote base systems, in the form of designing a system essentially "the way I think a system should be."</p>

<p>App_Rpt was started, not only to demonstrate this feature of Asterisk, but to essentially provide an outlet of nearly 30 years of experience and frustration with repeater and remote base systems, in the form of designing a system essentially "the way I think a system should be."</p>

<p>I learned from and was inspired by some of the best ideas and implementations and also from some of the worst, and tried to create a workable and desirable system that met as many needs as possible.</p>

<p>I learned from and was inspired by some of the best ideas and implementations and also from some of the worst, and tried to create a workable and desirable system that met as many needs as possible.</p>

<p>My first big hurdle was to design a radio interface that cound interconnect with a PC internally and the typical interface signals of a two-way radio. In the interest of keeping the technology simple and inexpensive, I designed a board (the ARIB board) which interfaced 2 analog FXS ports (either on a multiport analog card, like the [http://www.digiumcards.com/tdm400p.html Digium TDM400P], or a channel bank connected to the PC through a T1 card, that is already part of an existing phone switch) to the Radio signals (and provide buffering, level control, etc).</p>

<p>My first big hurdle was to design a radio interface that could interconnect with a PC internally and the typical interface signals of a two-way radio. In the interest of keeping the technology simple and inexpensive, I designed a board (the ARIB board) which interfaced 2 analog FXS ports (either on a multiport analog card, like the [http://www.digiumcards.com/tdm400p.html Digium TDM400P], or a channel bank connected to the PC through a T1 card, that is already part of an existing phone switch) to the Radio signals (and provide buffering, level control, etc).</p>

===Analog Radio Interface===

===Analog Radio Interface===

[[File:AnalogRadioInterface.jpg|left|thumb|Rev. C. Analog Radio Interface Board]]

[[File:AnalogRadioInterface.jpg|left|thumb|Rev. C. Analog Radio Interface Board]]

<br clear=all>

<br clear="all">

<p>This interface <i>did</i> work well to allow me to do the initial development of the software, and first half a dozen deployments, since most of us that had it first already had Asterisk phone switches already in opertion, with spare ports on our channel banks.</p>

<p>This interface <i>did</i> work well to allow me to do the initial development of the software, and first half a dozen deployments, since most of us that had it first already had Asterisk phone switches already in operation, with spare ports on our channel banks.</p>

<p>The systems were originally deployed in Northern California ([http://www.city-data.com/city/Oakhurst-California.html Oakhurst] area) at a couple of locations, and in San Diego by Steve, WA6ZFT.</p>

<p>The systems were originally deployed in Northern California ([http://www.city-data.com/city/Oakhurst-California.html Oakhurst] area) at a couple of locations, and in San Diego by Steve, WA6ZFT.</p>

<p>With Steve's greatly appreciated help, we were able to debug the thing and add many new and interesting features.</p>

<p>With Steve's greatly appreciated help, we were able to debug the thing and add many new and interesting features.</p>

===PCI Radio Card===

===PCI Radio Card===

[[File:PCIradiocard.jpg|left|thumb|Quad PCI Radio Card]]

[[File:PCIradiocard.jpg|left|thumb|Quad PCI Radio Card]]

<br clear=all>

<br clear="all">

<p>After a few months of the system running stably (despite new additions all the time), we decided that better system integration was appropriate, so we (along with help from David Kramer) designed and produced the Quad PCI Radio Interface card. This allows interface between the PC and 4 separate radio systems simultaneously, via 8 pin modular connectors.</p>

<p>After a few months of the system running stably (despite new additions all the time), we decided that better system integration was appropriate, so we (along with help from David Kramer) designed and produced the Quad PCI Radio Interface card. This allows interface between the PC and 4 separate radio systems simultaneously, via 8 pin modular connectors.</p>

===USB===

===USB===

[[File:Urirearview.jpg|thumb|left|DMK Engineering URI]]

[[File:Urirearview.jpg|thumb|left|DMK Engineering URI]]

<br clear=all>

<br clear="all">

<p>After looking at many possibilities, including usage of a PC's internal audio subsystem (yuch! yuch! yuch!), it sure seemed that the only realistic chance we had was to get something reliably working with a USB interface.</p>

<p>After looking at many possibilities, including usage of a PC's internal audio subsystem (yuch! yuch! yuch!), it sure seemed that the only realistic chance we had was to get something reliably working with a USB interface.</p>

today's standards (not to mention the horrendously pessimal

today's standards (not to mention the horrendously pessimal

environment in which they had to run), and still cost upwards

environment in which they had to run), and still cost upwards

of $1000 each. Most of these cards ended up being really bad

of $1,000 each. Most of these cards ended up being really bad

sounding and flaky personal answering machines.</p>

sounding and flaky personal answering machines.</p>

<p>In 1985 or so, a couple of companies came out with

<p>In 1985 or so, a couple of companies came out with

pretty-much decent 4 port cards, that cost about $1000 each

pretty-much decent 4 port cards, that cost about $1,000 each

(wow, brought the cost down to $250 per port!). They worked

(wow, brought the cost down to $250 per port!). They worked

MUCH more reliably then their single port predecessors, and

MUCH more reliably then their single port predecessors, and

<p>But to my dismay, no one had done anything about this. What I hadn't

<p>But to my dismay, no one had done anything about this. What I hadn't

realized was that my vision was 100% right on, I just didnt know

realized was that my vision was 100% right on, I just didnt know

that *I* was going to be one that implemented it.</p>

that '''I''' was going to be one that implemented it.</p>

<p>In order to prove my initial concept I dug out an old Mitel

<p>In order to prove my initial concept I dug out an old Mitel

MB89000C "ISDN Express Development" card (an ISA card that

MB89000C "ISDN Express Development" card (an ISA card that

it to show me how to format (well at least to be functional)

it to show me how to format (well at least to be functional)

a minimal Linux driver. So, I ported the BSD driver over to

a minimal Linux driver. So, I ported the BSD driver over to

Linux (actually wasnt *that* difficult, since most of the

Linux (actually wasn't '''that''' difficult, since most of the

general concepts are roughly the same). It didnt have

general concepts are roughly the same). It didnt have

support for loadable kernel modules (heck what was that? in

support for loadable kernel modules (heck what was that? in

kernel with it included). Since my whole entire experience

kernel with it included). Since my whole entire experience

with Linux consisted of installation and writing a kernel

with Linux consisted of installation and writing a kernel

module, I *knew* that it *had* to be just wrong, wrong,

module, I '''knew''' that it '''had''' to be just wrong, wrong,

wrong, full of bad, obnoxious, things, faux pauses, and

wrong, full of bad, obnoxious, things, faux pauses, and

things that would curl even a happy Penguin's nose hairs.</p>

things that would curl even a happy Penguin's nose hairs.</p>

<p>At the time, Asterisk was a functional concept, but had no

<p>At the time, Asterisk was a functional concept, but had no

real way of becoming a practical useful thing, since it

real way of becoming a practical useful thing, since it

didnt, at that time, have a concept of being able to talk

didn't, at that time, have a concept of being able to talk

directly (or very well indirectly for that matter, being that

directly (or very well indirectly for that matter, being that

there wasnt much, if any, in the way of practical VOIP

there wasn't much, if any, in the way of practical VOIP

hardware available) to any Telecom hardware (phones, lines,

hardware available) to any Telecom hardware (phones, lines,

etc). Its marriage with the Zapata Telephony system concept

etc). Its marriage with the Zapata Telephony system concept

doing this project? Have you ever thought of how incredibly

doing this project? Have you ever thought of how incredibly

many things that he has to concern himself with, and that it

many things that he has to concern himself with, and that it

just *NEVER ENDS*! At this point, I believe that I have

just '''NEVER ENDS'''! At this point, I believe that I have

worked with him on this project longer that just about

worked with him on this project longer that just about

anyone, including some of his employees, and believe me, I

anyone, including some of his employees, and believe me, I

have a good vantage point to see at least some of the stuff

have a good vantage point to see at least some of the stuff

that he has to go through to accomplish this.</p>

that he has to go through to accomplish this.</p>

<p>Personally, I would have *NEVER* taken on such a task, being

<p>Personally, I would have '''NEVER''' taken on such a task, being

that I am and was quite aware of the level of responsibility required

that I am and was quite aware of the level of responsibility required

to do so.</p>

to do so.</p>

help with this project. Thank you for demonstrating that you

help with this project. Thank you for demonstrating that you

believe in it, and that you believe in us.</p>

believe in it, and that you believe in us.</p>