[VoIP] Various questions

[john jones]

I know Jim Burnham and I ( and probably lots of other
folks too) have used PIC's to generate various timing
signals ( for ring cadence, to take the constant
output of the Clare tones for Busy and Re-order and
for various alarm signals.

It would be nice to pull all of that together, either
as a modular system or as an integrated system.

The Cisco 3810 is a real nice ATA that does pulse/tone
and even SF interfaces with either FXS, FXO, or E&M
types.  You can put up to six interfaces.  Also, I
think people are starting to get good results with the
Motorola VT1005.  These can be had for $50 for a 2
port FXS model.


Keep us posted on your ideas!

Thanks!

John


--- David Josephson <david at josephson.com> wrote:

> Since the crossbar switch is once again on the
> agenda and has a bit more 
> of the back burner than before, I'm once again
> looking for various 
> pieces of the puzzle.
> 
> 1. What versions of Asterisk are compatible with
> Max's sf.patch?
> 
> 2. Is there a simplified how-to for setting up a
> Mitel Smart-1 as a 
> tone-to-pulse converter? I would like it to accept
> two digit codes 2x 
> through 5x and single digit codes 6 through 0,
> translate from tone to 
> pulse and go back to sleep.
> 
> 3. I have been corresponding with Steph about more
> elegant solutions for 
> DTMF conversion and precise tone plant than
> tone-to-pulse conversion. 
> Years ago I built low distortion tone plants for an 
> electronically-controlled xbar switch using wien
> bridge oscillators, 
> which are tunable. Today the implement of choice
> seems to be the 
> Teltone/Clare M921 chip which will produce any
> common tone pair for $6. 
> There's also a need for various configurations of
> tone converters. We 
> lay out small circuit boards all the time at the
> company here, so 
> getting a short run made would not be a problem.
> Steph suggests using a 
> form factor that would allow mounting on a standard
> 2" rack plate, much 
> as relays, resistors and repeat coils are mounted.
> Using a fairly dense 
> card edge connector permits 20 pins, which is a
> little tight if we are 
> to combine a lot of functions on one card, but
> reasonable if one card 
> does one thing. What would other people want?
> Besides tone plant and 
> decoders, a basic trunk circuit would be nice.
> 
> --
> David Josephson
> Santa Cruz, Calif
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