Rick,
Building a PBX is fairly simple, if you have the right hardware and =
software at your disposal.
The problem is that the software and hardware are not cheap.

For the hardware and software, I always use Dialogic (but there are =
cheaper sources).
A D41/ESC card will support 4 analogue lines. Youcan have upto 8 cards =
in one system.
Or, if you prefere, you can fit D300 cards that will accept an E1 =
(30xISDN) Again, you can have upto 8 cards in a system. There are =
variations on these cards for USA (T1) support.
The software is usually sold on a per/channel basis.
Parity software, now part of Dialogic, that is now all owned by Intel, =
do a product called VOS.
You can throw together a complete system in a matter of hours (if you =
know the language).
I've built complete systems, integrating with MS SQL Server and doing =
all sorts of strange things in a matter of days. Check out =
http://www.intel.com/network/csp/trans/dialogic.htm
Voice Mail, FAX support, SMS support, FTP, WEB etc etc are all =
available.

The advantage of using, for example D41/D300 cards is that DTMF, CLI etc =
is all built in. Also, the boards have DSP for audio prompt play back =
(at different qualities), speech recognition, voice capture and a whole =
host of other features. All on a half or full size ISA/PCI card.

Also, remember that there is legislation about what you can connect to =
the phone network.

You might want to look into using TAPI. There are some TAPI boxs around =
that might do what you want. Also, TAPI is supported under Windows 2000 =
so you could write the software in Visual Basic or C++.




On Wed, 2002-07-24 at 21:10, Rick Mann wrote:
> I've been frustrated by a lack of phone systems to suit my needs. =
Either
> they're too expensive (100+ port systems for thousands of dollars) or
> they're close, but not quite. The best thing I found seemed to be the =
BizFon
> (http://www.bizfon.com/), but after adding all the required options, I =
still
> didn't come up with what I wanted.
>
> So, I got to thinking: if I could build a box with a FireWire or USB =
port,
> then write software on my computer to drive it, I could come up with
> something great and easily extendible.
>
> I would like to build a hardware device that can connect to 8 or so =
POTS
> lines, and 8 analog phones. It needs to be able to handle incoming =
data like
> Caller ID data, and needs to be able to generate similar data =
(CallerID,
> message waiting indications, etc). for the phones connected to it. If
> there's a standard for digital phones, I'd like to try to support it, =
as
> well.
>
> It needs to be able to connect any CO port to any extension, and it =
needs to
> be able to digitize audio on any port, and output audio to any port. I =
plan
> to let the host computer handle the decision-making (recognizing DTMF =
tones,
> routing callers, etc.) and recording management (playing the right
> greetings, routing messages). And it needs to be able to handle a =
certain
> amount of simultaneous work.
>
> I know very, very little about how phones work. I have some notion =
that
> there are isolation needs to be met, and that voltages change to ring, =
etc.
> I know about A/D and D/A conversion. I know basic embedded development =
(I've
> done PIC work and SH2 work), although I'm not sure what processor I'd =
use
> for something like this, although I suspect something like a StrongARM =
or
> Embedded PowerPC is called for.
>
> I suspect that there are ICs for handling a lot of phone-related =
stuff, too.
>
> I'd appreciate advice and info about vendors of such chips, design =
ideas,
> literature, anything you think might help. Thank you very much.
>
>
> --
> Rick
>
> --
> http://www.piclist.com#nomail Going offline? Don't AutoReply us!
> email listserv@mitvma.mit.edu with SET PICList DIGEST in the body
>
>

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