Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!accuvax.nwu.edu!nucsrl!telecom-request
From: ames!ames!claris!portal!cup.portal.com!John_David_Galt@uunet.uu.net
Newsgroups: comp.dcom.telecom
Subject: Re: Bell "Numbering Plan Area" Scheme Was Shortsighted
Message-ID: <5287@accuvax.nwu.edu>
Date: 17 Mar 90 20:11:21 GMT
Sender: news@accuvax.nwu.edu
Organization: TELECOM Digest
Lines: 72
Approved: Telecom@eecs.nwu.edu
X-Submissions-To: telecom@eecs.nwu.edu
X-Administrivia-To: telecom-request@eecs.nwu.edu
X-Telecom-Digest: Volume 10, Issue 180, Message 7 of 9


In the USA, the only case where timing must be considered is when the
first digit you dial is 0.  The zero could be the whole number.  What
follows is the rest of the scheme, which allows ALL other cases to be
distinguished by their initial digits (usually the first two, but
sometimes as many as nine).

Here are the "old" and "new" systems as best I understand them.  At
present a few crowded area codes use the "new" system and the rest use
the "old."  I predict that in a few years all of USA + Canada +
carribean will have to go to the "new" system, because we will have
run out of area codes possible under the "old" system.  (Under the old
system an area code must have first digit in range 2-9, second 0-1,
third any.  New system allows second digit to be any, so the set of
possible codes increases by a factor of five!)

Old system:

First digit 0, second 0 = long distance operator "00", total length = 2.

First digit 0, second 1 = International call.  This case IS ambiguous, but
   the ambiguity is not a result of the US system, and you can tell the
   network you are done by hitting "#" at the end.

First digit 0, second 2-9 = Operator assisted call.  Ignore the initial zero
   for purposes of determining length.

First digit 1, second 0 = First five digits are a company code, then figure
   the total length as if the company code were omitted.

First digit 1, second 1 = Special function, length set by local phone co.
   (For example, "1170" turns off my Call Waiting.)

First digit 1, second 2-9 = The initial "1" is ignored, figure the length using
   the rest.

First digit 2-9, second 0 = Area code + number, total length = 10

First digit 2-9, second 1 = Check third digit to catch the special cases 411,
   611, and 911 (total length = 3).  Otherwise it is area code + number = 10.

First digit 2-9, second 2-9 = Local number, total length = 7

New system:

First digit 0, second 0 = same as old system

First digit 0, second 1 = same as old system

First digit 0, second 2-9 = 0 + area code + number, total length = 11.  (Yes,
   the new system requires the area code on operator assisted calls to your own
   area code.  Los Angeles does not yet have this but San Francisco does.)

First digit 1, second 0 = same as old system

First digit 1, second 1 = same as old system

First digit 1, second 2-9 = 1 + area code + number, total length = 11

First digit 2-9 = Check second and third digits to catch the special cases 411,
   611, and 911 (total length = 3).  Otherwise local number, total length = 7

Also, for those of you who aren't from here and haven't heard:
California will soon have TWELVE area codes!  The new ones are 510
(effective 10/7/91, covers the East Bay section of what is now 415)
and 310 (2/1/92, western Los Angeles County).

Have a phone time!  :)

    --->  John_David_Galt@cup.portal.com   
  (There IS no save vs. puns!  Ahhahahaha!)