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From: straka@ihlpf.ATT.COM (Straka)
Newsgroups: sci.electronics
Subject: Re: Phone systems
Message-ID: <1261@ihlpf.ATT.COM>
Date: Thu, 19-Mar-87 15:08:27 EST
Article-I.D.: ihlpf.1261
Posted: Thu Mar 19 15:08:27 1987
Date-Received: Sat, 21-Mar-87 06:38:30 EST
References: <1443@ncr-sd.SanDiego.NCR.COM> <642@oliveb.UUCP> <2281@tektools.TEK.COM>
Organization: AT&T Bell Laboratories - Naperville, Illinois
Lines: 24
Summary: Display of calling number.

> If both phones are on the *same* CO, is it possible to have a box that
> will display the phone number of the calling party?  Can this only be
> done with the cooperation of the phone company, or is there some
> device I can connect to my end of the phone line?

Technology exists within telcos to transmit this kind of information
from office to office (and is COMMONLY done).  This is known as
SIGNALLING in the business.  Newer and newer methods are being used, and
eventually, ISDN will be able to practically bring this signalling
information to the residence.

The 2B+D of the basic ISDN lines are 2 channels of 64Kbit voice/data or
whatever, + one 16Kbit channel of signalling information.  Don't hold
your breath, since the telcos will want much assurance that you will
want to pay the $$ for these kind of services before they will invest
the enormous sums of money to make ISDN available for residence
customers.

Practically, you won't see it soon, since (even if you could handle
signalling from your phone to the central office) it would require a lot
of hardware and programming for old switches to provide this service.

-- 
Rich Straka     ihnp4!ihlpf!straka