Caller ID: The Facts (Autumn, 1990) 
By Jake "The Snake"
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You've probably either heard of it, seen it in the media, or maybe you even own
one of these little "buggers."  There's been a lot of talk, fighting, and
discussions in court over the Caller*ID box. Currently existing only in New
Jersey, this device is basically a tracer. And, yes, it is legally available to
the public.

In case you aren't aware of such a hacker's dream, let me fill you in on the
details. The device itself is a small stand-alone unit, about 6 inches by 4
inches, weighing about 8 to 10 ounces, with a 32-character (5-by-48-pixel),
two-line display and a few buttons on the front. In size it resembles a simple
desktop calculator from a couple of decades ago. It can run on a 9 volt or AC
adapter and has two RJ-11 jacks on the back, both identical, for attachment to
wall and phone.

Caller*ID is offered along with many other "sister" services that I will
explain later. Because of the AT&T divestiture a few years back, the local
companies aren't authorized to sell the device itself but can only offer the
service (at a cost of $21 for installation and a whopping $6.50 a month) to its
customers. The box can be ordered from a few different distributors for
anywhere between $60 and $300.

Let's say you purchased a Caller*ID (known as "ICLID" in the industry, which is
an acronym for Incoming Call Line Identification Device) and hooked it up to
your phone. This is how it would work: After your phone rings once, you'll see
some information flash on the little LCD display. Models vary, but you'll
definitely see the caller's phone number and current time and date. Most models
store the numbers in memory for recall at any time. So, if you re not around to
answer the call, you can be sure that anywhere from 14 to 70 numbers will be
saved for your convenience. (It's great to be able to come home and see X
number of messages on your answering machine and see X+4 callers on your ICLID.
With a little matching up, you can figure out who didn't leave a message.)

Of course, there are drawbacks to our little "mirror box."  What are the
limitations to its tracing ability? First of all, it won't work without the
local company providing the service. Only after the first ring does the
information come storming down the line to be decoded by your little friend. (I
have two lines in my house, and sometimes there's a bit of crosstalk between
them. When the phone rings, if I listen carefully enough I can actually hear
the coded ICLID information being sent.) Also, only areas that offer this
service (and other "CLASS" Calling Services) to their customers will be
traceable areas. But this area is growing.

If someone calls from out of state or from the boonies a message like "Out of
Area" will be displayed instead of the number. That's the real bummer. But, all
of the latest models of Caller*ID devices are area code compatible and show
your area code where other NPAs will be in the near future. Many states have
been slow to pick up the technology mainly because of political and legal
reasons. Many privacy issues have been suggested and debated over, but we won't
go into those here. As I understand it, New Jersey Bell contends that if a
person has your number and calls you, you should have their number as well;
when a connection is made, both ends should know who they re talking to. So,
hopefully other states will get in gear.

The option to block particular calls is being juggled around, too. Telephone
companies are thinking of offering a service whereby the customer would dial a
couple of digits before the seven digit number and the receiver would get an
"Out of Area" or similar message on their ICLID display. This would definitely
suck, unless you are the caller. But this service is already available now
thanks to a small loophole. I'll explain later.

New Jersey Bell started CLASS Calling Services around December of 1987. They
were test marketed in Hudson County until December 1988 and then began to
spread. Other services include Priority*Call, Call*Block (a personal favorite),
Repeat*Call, Select*Forward, Return*Call, Call*Trace, Tone*Block, and others.
Many of these are based upon the instant tracing ability of CLASS.

Priority*Call will send you a distinctively different sounding ring when
certain people call you. You program a "queue" of phone numbers that, when
called from, will sound different than the standard phone ringing.

Call*Block is lots of fun. Again, you can program a queue of people into your
phone (really, the phone company's computer). When they call your line, they
get a recorded message along the lines of, 'I'm sorry. The party you have
reached is not accepting calls from your telephone number." Nice and rude.

Call*Trace is a service that is available to everyone on a pay-per-trace basis.
If you receive a prank, etc. you hang up, pick up, and immediately dial *57. A
recording lets you know if the trace was good or bad, and you get charged $1.00
accordingly. Unfortunately you have to call the phone company to get the phone
number. This service is for serious complaining and is meant for people who get
pranked a lot and want to file charges.

All of the above features can be generally replaced with ICLID. As a substitute
for Call*Block I can simply not answer the phone if I don't want to speak to
someone, since my ICLID lets me know who it is. Of course, that prerecorded
message adds a nice touch. Call*Trace is pretty much useless with ICLID unless
you want to bring in the Gestapo. But, then again, Call*Trace is open for
anyone to use and isn't ordered monthly like the other services.

A woman from New Jersey Bell told me, though, some technical legalities
regarding Call*Trace and Caller*ID. If someone pranks me, and I return their
call (having read their number from my "mirror box") and prank them in return,
they can *57 me and sue me for phone harassment. Even though I have their
number on my ICLID, if I don't *57 him before I call him back, I get my ass
kicked in. So, the moral of the story is that ICLID can't be used as evidence
of a prank.

Select*Forward is used in connection with Call Forwarding and simply forwards
only calls coming from numbers that you choose.

Repeat*Call doesn't have much to do with identifying the caller, but will
simply redial a number until you get through, and then call you back when the
line is free, allowing you to use the phone for other reasons. Sounds cool, eh?
Now you can get through to any radio station you like, right? Wrong. It really
isn't as great as it sounds. First of all, it only "redials" for 30 minutes.
Also, it really doesn't dial the number, but only checks to see if the line is
free (and it checks only every 45 seconds). So, it is possible, and happens to
me occasionally, that you pick up the phone when the computer calls you back to
inform you that the line is free, and you find that it's busy again!)

Return*Call is made for people who just make it out of the shower and to the
phone a second after the caller hung up. Boo hoo. In a few keystrokes the call
is returned, and the wet, naked person still has no idea what number (s)he
returned.

And finally, Tone*Block turns off call-waiting for individual calls. Pick up
the phone, dial *70 and then the number. Voila! No interruptions. But let's say
someone calls you. You cannot turn off your call-waiting in this case, unless
of course you also have 3-Way Calling. If you do, you may switch over to the
other line and *70 yourself and you'll be fine for the call.

With instant tracing ability soon to sweep the nation, what's the nightmare?
Well, basically the hacker's dream is not only for the hacker but for anyone
who s got the cash and happens to live in a CLASS infested area. With the
public being offered these services, imagine what business customers, or even
Sprint/MCI/AT&T are being offered? When ICLID capabilities spread to more
states, LCD displays will be showing more and more area codes. Eventually,
long-distance companies will integrate themselves, and for every telephone
connection made, there will be two numbers involved and available to each end.

When I first got Caller*ID (the service was actually enabled on my line before
I received the box) I wanted to learn as much about it as I could. So I played
around with it and took it apart. The model that I have (which is relatively
old, but there are more ancient ones, too) has a main board inside with some
chips and components on it. By ribbon cable it is hooked to an LCD board with
LSI chips. There are two buttons (Review and Delete) up front and a battery
clip in the back. When the 30th call comes through, it scrolls old ones off to
make way for the newest. (This has happened only once to me when I was away for
an extended weekend.) What I like about my model is that it will store every
call separately. On many models these days, if a call comes through more than
once in a row (from the same number), the series of calls will appear under
just one entry with a small "RPT" indicator for  repeated call.  Personally, I
like to know that a certain person called twice a minute for five minutes to
get a hold of me, rather than just "Repeat." But that's a personal preference.
The flip side is that the extra calls take up space in memory.

The main distributor for ICLIDs is Bell Atlantic Office Supplies. They sell a
few different models. Sears has also been allowed to sell ICLIDs through AT&T
(who has yet another company making them). Any Sears in New Jersey will sell
you one for around $89.95. Radio Shack expects to be offering one soon. That's
about it for being able to order them. But there are of course the
manufacturers that build these things. Sometimes you can order directly....

Currently, there are only four manufacturers around that I know of. In Irvine,
CA is Sanbar, Inc. Sanbar works jointly with another company called Resdel
Communications, Inc. I was able to acquire some helpful information through
Sanbar and their technical support. Colonial Data Technologies is located
somewhere in the depths of Connecticut and makes most of the ICLIDs that Bell
Atlantic and Sears/AT&T sell. They aren't too helpful when it comes to
questions about Caller*ID. RDI in New Rochelle, NY recently created a smaller
company, CIDCO, to produce ICLIDs, as the etymology of the name might suggest.
(I spoke with a fellow there named Bob Diamond. I was pretty embarrassed when,
after a few conversations with him, I curiously asked what RDI stood for and
found out it meant "Robert Diamond, Inc.") The other manufacturer is a major
telephone equipment supplier. Northern Telecom has a massive set of complexes
in the southern United States. They make a standalone ICLID as well as the only
living telephone with a Caller*ID display built in. It's known as the Maestro
and can be ordered through Bell Atlantic. It's a simple thing with your basic
features such as one-touch dialing, redial, hold, mute, etc.

One thing I aspired to do with my tracer was to try and interface it with my
computer. If I could just get the information on the LCD to the serial or
joystick port, I could write lots of fun programs. You're sleeping in bed and
the phone rings. Unfortunately you re too tired to get up, turn on the light,
and see who's calling. (Actually, CIDCO makes an ICLID with a backlit LCD
display.) But you left your computer running and within a few milliseconds it
announces the person s name, and a Super VGA digitized picture flashes on the
screen. Now you know who it is.

And the imagination can run wild with things to do with the computer integrated
ICLID: auto-validating BBSs, database management, and so on. So I called Sanbar
(the manufacturer of mine) and talked to one of the head engineers. I asked him
if there was any way to leech information from the unit. He said that piping it
off the LCD was the best bet, but it might be easier to build a whole ICLID
from scratch. After speaking with many people from many different companies, I
finally worked on outputting from an LCD. Sanbar used a Sharp LM16255. From
Sharp (who was very friendly and helpful) I received literature and
specifications. Unfortunately I didn't get too far. Apparently the information
is sent in nibbles to the LCD board in parallel format. One must know a bit
about electronics and parallel port communications to wire it up.

But fortunately, now there is at least one box available that sends the
information via a serial port. (Ah! Such ease.) CIDCO is selling a "business
model" that sends the information at 1200,N,8,1 through a serial port in the
back. The price? $300. Too much for me. Other companies said they will have
similar items, which I expect to be much cheaper.

As far as I know, there aren't many tricks or secrets about using your ICLID at
home. When someone calls, either you get their number or you don't; I don't
think any electrical modifications will be able to trace untraceable numbers. I
hope I am wrong. When I first read the instruction "manual" (leaflet is more
like it) I saw that Bell Atlantic had put a piece of tape over a part of the
page. I guess they didn't have time to edit the paragraph out. It was in the
section of text showing all the different messages that my box could produce.
(It can either show a) a phone number; b) "Out of Area,"; or c) a junk number
with a few question marks, indicating that there was static on the line or the
phone was picked up during the information transmission after the first ring.)
Looking at it through the light I saw that another possible message it could
produce (and doesn't anymore) was "Private No." I thought that was great! After
speaking with New Jersey Bell, I found out that unlisted numbers are traced
along with everything else! Pretty awesome; New Jersey Bell doesn't skimp.

If you have call-waiting, you'll hear the tone, but unfortunately the ICLID 
won't trace the number. It needs that first ring to "wake it up," so the phone
company doesn't bother to send any info. They tell you this in their brochures,
but they don't tell you how you can still trace the number of the person who
calls you (without going through *57, the main office, and a law enforcement
agent). Here is how to do it: When you hear your call-waiting, tell your friend
that you'll call her back and hang up the phone. They will be disconnected and
the phone will begin to ring for the person who originally clicked in.
Call-waiting leaflets tell you this will happen, but no one tells you what
happens next, after that first ring. Voila! Your ICLID will light up and will
translate the data that was sent after the first ring. You've traced a
call-waiting!

As I mentioned earlier, the idea of a per-call block is being thrown around in
courts and behind telephone company doors. Supposedly, soon you will be able to
make "Private No." show up on your adversary s LCD display when you call. But,
it's quite possible now. If you want to call someone and not have your number
traced, all you need is a bit of plastic. No "boxes" or equipment. By going
through your Sprint/MCI/AT&T calling card, the received will see an "Out of
Area" message. That's what the phone company displays when the incoming call
originates through a calling card. Voila! A blocked call. The only drawback is
that small surcharge for using the card.

Recently, New Jersey Bell corrected a small computer bug that a bunch of
friends and I were having a lot of fun with. When someone called my house
collect, the number of their pay phone would show up, so I could reject the
call and return it, paying nothing for the connection (assuming the pay phone
was a local call). That didn't last for long, and now a collect call brings
with it the anonymity of an "Out of Area" message. It was fun while it lasted.