[comp.dcom.telecom] How Exactly Do Private Pay Phones Work?

smk@attunix.att.com (S M Krieger) (07/01/89)

I recently needed to make a long distance call, and the only public
telephone available was one of those new private pay phones.  It
did not support 10xxx LD carrier selection, but my coinless call
to '0' got me the local telco operator, who then, at my request,
connected me to an AT&T operator.

Now, I'd like a little education on exactly how these private
phones work; for example,

	1.  If I am going to deposit coins to pay for the call,
	    what is computing how much I pay?   Is it the
	    central office, or is it some computer in the phone
	    itself?

	2.  Will these phones connect me free of charge to a
	    local telco operator,  or could even a single '0'
	    connect me to some pre-selected LD operator?

	3.  If I make a call from these phones without ever deposting
	    any coins, does the phone owner get any revenue from
	    the call (e.g., in my case, '0' got me to a telco
	    operator, she connected me to an AT&T operator, and the
	    call was billed to my AT&T Calling Card.  I wasn't misled
	    by anyone; the call did show up on my AT&T bill a few
	    days ago)?

	4.  Am I entitled to 10xxx LD carrier selection if I use
	    one of these phones?
--
Stan Krieger
Summit, NJ
 ...!att!attunix!smk

pdg@chinet.chi.il.us (Paul Guthrie) (07/03/89)

In article <telecom-v09i0220m02@vector.dallas.tx.us> smk@attunix.att.com
(S M Krieger) writes:
>Now, I'd like a little education on exactly how these private
>phones work; for example,
>	1.  If I am going to deposit coins to pay for the call,
>	    what is computing how much I pay?

With COCOT type phones (Intellicalls, Alcatels, etc) the phone itself computes
the rates.  The methods they use are not as complex or accurate as most
LD carriers.  They mainly have NPA+NXXs stored in a table mapping to
rate centres.  They then store latas and V&H coordinates of the rate
centres and compute distance to look up in mileage band tables for combos
of inter/intra state/lata calls.  Tax is often added at a highest possible
rate.  In short, they take shortcuts, and generally compute a higher
than normal rate to cut down on the amount of memory needed for the
ROM based tables.  These tables are often out-of-date.  Some of the newer
phones have modems in them to receive downloaded rates from a PC program.

>	2.  Will these phones connect me free of charge to a
>	    local telco operator,  or could even a single '0'
>	    connect me to some pre-selected LD operator?

They can be programmed either way.  The amount of options for dialing plans
on these things is huge.

>	3.  If I make a call from these phones without ever deposting
>	    any coins, does the phone owner get any revenue from
>	    the call

No.  It's part of the price of doing business.

>	4.  Am I entitled to 10xxx LD carrier selection if I use
>	    one of these phones?

Not really.  I've even seen them programmed to take the 10xxx and still
send the call through the AOS (transparently).

Of course, none of these comments apply to BOC phones necessarily.
--
Paul Guthrie
chinet!nsacray!paul

johnl@harvard.harvard.edu (John R. Levine) (07/04/89)

In article <telecom-v09i0220m02@vector.dallas.tx.us> smk@attunix.att.com
(S M Krieger) writes:

>	1.  If I am going to deposit coins to pay for the call,
>	    what is computing how much I pay? ...
If it's a real telco pay phone, central equipment computes the charge.  If
it's a COCOT (Customer Owned Coin Operated Telephone) it's generally a computer
in the phone itself.  That's why COCOTs cost over $1000 while regular pay
phones are closer to $500, even though they're externally the same.

>	2.  Will these phones connect me free of charge to a
>	    local telco operator,  or could even a single '0'
>	    connect me to some pre-selected LD operator?
Technically, the COCOT can do whatever it wants.  Legally, most places seem
to require that 0 give you someone who can complete emergency calls 24 hrs
a day, and pragmatically that means the telco operator.

>	3.  If I make a call from these phones without ever deposting
>	    any coins, does the phone owner get any revenue from
>	    the call ...
Ho ho.  If you place an inter-lata calling card call from one of these things,
it will invariably route you to an "alternative operator service" such as NTS
or ITI who will charge you several times the AT&T rate for the call.  For
intra-lata calls, it depends on the state tarriffs; if your call is carried by
a real phone company such as AT&T, Sprint, or the local BOC, the phone owner
doesn't get a cut.  If it's an AOS, they probably do.  I've seen ads in the
business pages of the local paper saying "get $1.00 per call when customers
use your payphone."

By the way, the magic of equal access is now coming to real telco pay phones,
so that if you dial 0+number your call gets routed to the LD carrier of the
phone owner's choice. If it's NTS or ITI, you pay the same exorbitant rates.
Check the instruction plate of the phone; it legally has to say who carries
the LD calls, and the operating companies are pretty good about making sure
they tell the truth. (They're no fonder of NTS or ITI than is anyone else.)

>	4.  Am I entitled to 10xxx LD carrier selection if I use
>	    one of these phones?
Yes you are, although many of them are programmed, probably illegally, to
make that difficult or impossible.  I've also had them ask me for $9.95 when
I dialed 950-1022.  What a bunch of slimeballs.
--
John R. Levine, Segue Software, POB 349, Cambridge MA 02238, +1 617 492 3869
{ bbn | spdcc | decvax | harvard | yale }!ima!johnl, Levine@YALE.something
Massachusetts has 64 licensed drivers who are over 100 years old.  -The Globe