TELECOM Digest OnLine - Sorted: [TELECOM] Re: Area Codes and Prefixes, esp. 200

[TELECOM] Re: Area Codes and Prefixes, esp. 200

Mike Z (
Thu, 01 Mar 2007 07:22:23 +0000

PAT: please do NOT display my email address!

Neal McLain wrote:

> Therefore, I agree with Goudreau: 201-200-0000 is the lowest
> numerically in the NANP.

> And I suppose that:

> If you're counting dial pulses, the lowest would be 212-221-1111,
> except that it might be tied with 212-212-1111 if the Illinois
> Commerce Commission were assigning NNXs in New York.

The Illinoix Commerce Commission doesn't assign central office codes.
Neustar's NANPA does. Since overlays with mandatory 1+ ten-digit
dialing exists in New York City, then it is quite possible that NANPA
might ultimately assign a 212-212 code, as well as a 646-646 code,
718-718 code, and so forth. At present, there are no such codes
assigned within New York City, where the numerics of the office
code duplicate their own area code. So the lowest theoretical
number in the NANP, counting dialpulses, would still be
212-212-1111. Note that the N11 codes are not assignable as
Area Codes nor as "real" office codes within an area code, thus
you can NOT have 211+NXX nor NPA+211 at present as real
area+office codes.

> The highest numerically would be 989-999-9999, in an unassigned
> NPA-NNX in Michigan.

> The highest counting dial pulses would be 909-900-0000, an
> unassigned number in the Fantana, California rate center.

Actually, the highest theoretical dialpulse-counted NANP number would
be 900-900-0000. At present, there is no service provider who is
assigned the premium-rate 900-900 code, but that code is also not
restricted from possible future assignment by Neustar. And at one
time, NANPA might actually have had made a 900-900 code assignment
that was later reclaimed by, or returned to, NANPA, since SAC 900 has
never been "stable".

A few days ago, Patrick Townson wrote:

> There _is_ an 'area code 200', or more precisely it is a special
> service code. 1-200-highly secretive seven digits does a
> 'ring back' to the calling number. The seven digits following
> 1-200 differ from one central office to the next, and within that
> CO, they tend to change the number every two or three months, mainly
> because outside plant technicians used to get bribed a lot (maybe
> still) by phone phreaks looking for the number. You can try
> 1-200-your own number and if a tone signal is returned, then hang
> up. If your phone rings back at you, then you win, if not, then you
> lose. _That_ (200 plus own number) used to work in Chicago when they
> first did away with 571-6, but I dunno any longer.

This use of 200 followed by seven-digits is NOT an area code no matter
how you want to describe it. It is strictly a plant test type of code
and has no universal application as such. Most central offices in the
US and Canada have some kind of "ring back" test dialing procedure,
and while there are "patterns" that can be seen, there is NO
uniformity at all.

Your one-time Chicago use of 1+200 followed by seven-digits is just
that, a one-time Chicago "only" use of 200 as a plant test code for
that function.

Other areas used a three-digit "NXX" type of a code followed by the
last four-digits, not the full seven-digits, for "ring back" purposes.

It is also possible that many parts of the NANP have used 200 as a
plant test code at one time or another for other test purposes, other
than "ring back", such as ANAC, reaching the test board, reverse
battery purposes, and so forth. Just because your one-time use in
Chicago of 200 for "ring back" does NOT qualify that function as a
universally recognized "area code".

As an "area code" in the NANP, at present, 200 is universally known to
be "unassigned" by Neustar, just as it was universally known to be
"unassigned" by Bellcore and before that "unassigned" by AT&T. It is
"earmarked" for some future "special services AREA code" in the NANP,
in the way that "special AREA code" 900 is premium rate, "special AREA
code" 800 and now 888, 877, 866, etc. when used as an AREA code in a
ten-digit number is for toll-free, etc.

Thus, Bob Goudreau is correct when he stated a few days ago that if
NANPA were to ever put area code 200 into service, i.e. 200 as a real
universally recognized "special services" area code, which would NOT
be a locally used plant test function in some places, then
200-200-0000 could be the lowest theoretical telephone number in the
NANP when looked at on a purely "numerical" basis. And for that
matter, theoretically, 200-200-0000 *IS* the lowest possible theoretic
numeric number in the NANP, although at present, SAC 200 is unassigned
but reserved for a future NANP-wide undefined special function along
the lines of premium rate 900, toll free 800/etc., personal numbering
500, etc., and the next triplet of '200' is a theoretical office code
yet to be assigned within that future to be assigned SAC 200. But of
course, this is all theoretical at present.

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