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From: john@bovine.ati.com (John Higdon)
Newsgroups: comp.dcom.telecom
Subject: Re: Payphones and DTMF Dialling
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Date: 20 Dec 90 10:02:32 GMT
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U5434122@ucsvc.ucs.unimelb.edu.au writes:

> Is it possible to use a tone-sender to dial from a
> payphone in USA or Sweden or elsewhere?

> If this is indeed TA's worry, how effective would such a simple fix as
> disabling the handpiece microphone until answer supervision be?

> [Moderator's Note: Disabling the mouth until supervision would prevent
> the phone from being used to call directory enquiries or the operator;
> both of whom answer unsupervised, no?  PAT]

Remember, we're talking COCOTs here. They GUESS at supervision, so
while DA, Repair, or the Operator do not supervise, this is irrelavent
to the COCOT. It hears a voice and then assumes supervision. Also,
most COCOTs don't present "real" dial tone to the user, but an
internally generated one. The user dials the number and the COCOT uses
its internal ARS tables to redial the call, sometimes adding codes to
use an AOS.

The fact of the matter is, virtually all COCOTs in the US are
installed on DTMF equipped lines. While it is possible to spoof most
of them in manners not to be mentioned here, the straightforward use
of a hand dialer is not one of them. Either the COCOT equipment is
weenie, or the owners/installers are ignorant to the built in security
it employs.


        John Higdon         |   P. O. Box 7648   |   +1 408 723 1395
    john@bovine.ati.com     | San Jose, CA 95150 |       M o o !