[VoIP] Numbering - 2C2 CTS

[Steph Kerman]

Mark Rudholm wrote:
> Steph Kerman wrote:
>> That's interesting! Semi-public service? What do you have to pay for 
>> that?
> The service is provided by SBC/AT&T. The intended market is Payphone 
> Service Providers (i.e. COCOT operators) who want to use real 
> payphones using telco-side billing/control (ACTS) rather than internal 
> logic. I use it simply because I have a couple 2C2s (one is new-old 
> stock!) a 1D2, and a 2D2.
>
> It's kind of expensive, about 65$/month after taxes.
>
> No, I haven't tried putting more than one payphone on it at a time. At 
> worst, I suspect it wouldn't work at all (since the coin tests 
> wouldn't work right) and at best, it'd be odd, since the coin relay in 
> all connected phones would actuate in unison.
That certainly would not be a problem with 3-slot phones on a CF line.  
The coin relay is disconnected unless there is a coin in the hopper.  I 
believe the same is true with single slot phones except that there is a 
ground isolation circuit to prevent ground noise.   A single slot phone 
provides 2 indications back to the CO: any coin present and initial rate 
present.  I suspect that phones with no coin on deposit would be 
completely passive to both tests as well as coin disposal attempts.  But 
there might be some problem with the Totalizer.  I just don't know.  So 
if I were you, I would try it.  There's nothing to lose.

In any case, you could always insert a simple relay concentrator between 
the coin phones and line so that only the first phone that attempts to 
seize the line is connected to it and the others are locked out.  Then 
you can put one of your less pristine looking 1D2s on a pedestal out by 
the street and earn some revenue to cover some of that $65/month 
expense!  Until your town zoning code enforcement people show up...

There is an arrangement to provide a manual answering extension on coin 
lines terminated in single slot CTSs.  The answering telephone contains 
a special circuit board containing a mercury wetted relay and a bunch of 
simple semiconductor devices.  I think one purpose of the circuit in the 
manual answering phone is to prevent it from interfering with outgoing 
calls to avoid loss of deposited coins.  The BSP does not contain a 
schematic of the circuit board and although I do have a sample, I not 
reverse engineered it... yet.  It might provide some insight into the 
issues involved in coin line sharing though.
> Oh, it's not a 17Q, it's a 1PC (the 17Q is, electrically, no different 
> from a regular business phone line, it's the 1PC
> that has the coin signaling). The 17Q is what they delivered at first, 
> in error.
>
> Dunno who your telco is, but for SBC/AT&T, go here:
> https://primeaccess.att.com/ (and click on "Payphone")
Thanks
> That site is interesting. You can buy pretty much anything these days 
> from AT&T if you're willing to pay for it. Such a change from the bad 
> old days when the telcos were fortresses and you couldn't so much as 
> order Touch-Tone service without proving that you hadn't stolen one of 
> their Touch-Tone phones.
Yes.  A different world.  Better in some ways and worse in others.

At the moment, the only coin phone I have set up, a 3-slot 2-piece 150G, 
is handled by a simple prepay adapter circuit I built a few decades 
ago.  (How time flies!)  The prepay adapter circuit is installed between 
the phone and the line circuit of my crossbar PBX.  It makes the phone 
function as a nickel prepay PBX extension with 9th level access to the PSTN.

Steph