[comp.dcom.modems] caller ID

TERRY@SPCVXA.BITNET ("Terry Kennedy, Operations Mgr") (03/16/90)

Dan Warburton  <warb@faatcrl.uucp> writes:
> I have caller ID a service from my local Bell company and keep thinking
> wouldn't it be nice if I could teach my Amiga to read the numbers being
> sent. Can any one tell me where I can get techical info on how the data
> is transmitted. This looks like a good group to ask. E-mail please I
> can't keep up with this group.  Oh and Thanks!!

  The caller ID signal is a series of simple coded pulses _before_ each
ring cycle. The reason two rings are "required" for detection is to make
sure it got the complete information (and it matched).

  There is a further problem - caller ID is not currently supported for
"out of LATA" calls. So, calls from distant area codes will show up as
"out of area" (on the consumer box Bell sells) and "?????" on an ATT dis-
play box. There is a complicated reason for this - if you're not inter-
ested, hit your skip key now...

  The calling party information is _not_ transmitted as a simple calling
phone number. It is actually a longer number which the phone company in-
ternally uses for identification purposes. A call from a digital switch
in your LATA is no problem, because _your_ switch (also digital) can get
the translation and display it. A call from outside your LATA will pass
infomation which your switch cannot translate, so you get "out of area"
displayed. A repeat caller can be detected because the information is the
same, even though the translation is not known, so you get "repeat" on
the display.

  While it certainly is possible to get inter-LATA number translation, it
would require additional networking support, and I expect that the Bell
companies are waiting to see how well the service sells before that step.

  Also be aware that in several areas, people are pushing for a way to
disable the feature, either permanently or on a per-call basis. It is un-
clear whether this would be an extra-cost service or part of the regular
rate.

  [I don't work for the phone company, haven't worked for any phone company
since before digital switches were used, etc. The above information is from
my experimentation with the service when it was being tested in Hudson
County, NJ. - for a while all phones had caller ID enabled during testing.
The service or signalling system may have changed since then, but I doubt it.]

        Terry Kennedy           Operations Manager, Academic Computing
        terry@spcvxa.bitnet     St. Peter's College, US
        terry@spcvxa.spc.edu    (201) 915-9381

rskaelber@miavx1.acs.muohio.edu (Randy Kaelber) (03/16/90)

In article <1261@faatcrl.UUCP>, warb@faatcrl.UUCP (Dan Warburton) writes:
> I have caller ID a service from my local Bell company and keep thinking
> wouldn't it be nice if I could teach my Amiga to read the numbers being
> sent. Can any one tell me where I can get techical info on how the data
> is transmitted. This looks like a good group to ask. E-mail please I 
> can't keep up with this group.  Oh and Thanks!!
> -- 

NO! Don't E-Mail it! Well, E-mail it to Dan, bu then post it for the rest of
us! Enquiring minds want to know!

################################################################################

 "Saved again by technology"        |     Randy Kaelber (H.R.H. King Lerxst II)
                                    |     Academic Computing Services
                                    |     Miami University, Oxford, Ohio

"Love responds to your invitation, Love responds to your imagination." 
                                                      -Neil Peart/Rush

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Disclaimer: "Steve Strassmann at MIT says I don't need one anymore. Any
complaints? Take them to HIM."

dave@westmark.UU.NET (Dave Levenson) (03/18/90)

In article <C42D4B31089F003131@SPCVXA.BITNET>, TERRY@SPCVXA.BITNET ("Terry Kennedy, Operations Mgr") writes:
(in reply to Dan Warburton  <warb@faatcrl.uucp>)
>   The caller ID signal is a series of simple coded pulses _before_ each
> ring cycle. The reason two rings are "required" for detection is to make
> sure it got the complete information (and it matched).

Almost correct.  In NJ, and probably elsewhere, the caller-id
information is sent as a string of ASCII characters at 1200 bps,
on an audio-frequency carrier, using FM (actually, FSK) modulation
(similar to, but not compatible with, the old 202 half-duplex
modems).  This data-burst is send once per call, after the first
ring.  There is no redundancy (other than a parity bit per
character) and no guarantee of error-free delivery.

-- 
Dave Levenson			Voice: 201 647 0900  Fax: 201 647 6857
Westmark, Inc.			Internet: dave@westmark.uu.net
Warren, NJ, USA			UUCP: {uunet | rutgers | att}!westmark!dave
[The Man in the Mooney]		AT&T Mail: !westmark!dave