From: "Philippe Nave" <pdn@dwroll.dw.att.com>
Date: Mon, 8 Nov 93 14:33:03 PST
To: cypherpunks@toad.com
Subject: Modem taps/Caller ID
Message-ID: <9311082230.AA29752@toad.com>
MIME-Version: 1.0
Content-Type: text/plain


The recent discussions of tapping modem transmissions reminds me of
a scrap of data I saw about Caller ID [the service provided by the 
phone company that displays the caller's phone number whenever your
phone rings]. Supposedly, the phone company transmits the caller's 
number as a burst of 1200 or 2400 baud ASCII between the first and
second rings; if your modem is set up 'just right,' you can capture
the number with a PC.

[Sorry there is so little data to go on; this tidbit appeared on a 
PC bulletin board and there was no follow-up discussion.]

Does anyone here know more about this? I would dearly love to set up a
program on the PC in my basement that could capture Caller ID data and
log it in a database. Obnoxious callers (Olan Mills, local telemarketers,
etc.) could be identified easily, and I could program the modem to pick
up / hang up on those calls. Then, I could ignore the phone until the
third ring; my PC would automatically dispose of nuisance callers as soon
as the Caller ID data was processed. Also, I'd build up a database of 
names and phone numbers important to me - maybe I'd spend less time 
scrounging my pile of Post-It notes looking for phone numbers.

........................................................................
Philippe D. Nave, Jr.   | The person who does not use message encryption
pdn@dwroll.dw.att.com   | will soon be at the mercy of those who DO...
Denver, Colorado USA    | PGP public key: by arrangement.