[comp.dcom.telecom] 8-Digit Phone Numbers vs. More Area Codes

smk@attunix.att.com (S M Krieger) (11/10/89)

Based on the number of area code splits that have recently occurred or
have been announced, I am wondering if the idea of just expanding our
phone numbers to 8 digits is being considered?  Doing that just
inconveniences all phone users eually and multiplies by 10 the number
of phone numbers that are possible within an area code.  On the other
hand, splitting an area code changes three digits of the phone number,
and only doubles the number of phone numbers that are available.

Also, based on the growth in the demand for phone numbers, a demand
incidentally which the phone companies are themselves encouraging
(i.e., the coded ring feature, or whatever it's "officially" called),
it seems that area code splits will need to occur even more often than
they do now.  For this, I am looking at my home state of NJ: a second
area code was created for NJ in 1958 (the 201/609 split), and now a
third area code (the 201/908 split) is being created.  Since it
probably won't be 30 years until the next split, and 30 years after
that until the fourth split, there has to be a better way to
"stabilize" our phone numbers.

Any ideas or thoughts?


Stan Krieger
Summit, NJ
 ...!att!attunix!smk

wb8foz@mthvax.cs.miami.edu (David Lesher) (11/12/89)

Stan Krieger asks about 8 digit phone numbers, and makes some good
points.  But, alas all is not simple.

On the human side, each existing user could get a number assignment of
NPA-old-nmbr0 so that no one would have to learn a new number. Then
new assignments could take the form of different last digits. This
would help ease the shock of the changeover.

The bad news is the technical picture. I suspect that EVERY piece of
switch equipment in the country (or n.a. for that manner--remember NPA
809?) would have have to modified to handle this. While the ESS's
might get by with what an old boss called "SMOP--simple matter of
programming", what will all the SxS, panel, X-bar et-al offices do? I
doubt the material or expertise exists to upgrade these, much less the
$$$$. (larry@kitty would be better source on this. My only time in
CO's has been tours) Then, what about all the millions of CPE
call-dialers?

But, all this said, we can assume we will be driven to such a change
eventually. Would we better to bit the bullet and do it now?


A host is a host & from coast to coast...wb8foz@mthvax.cs.miami.edu
no one will talk to a host that's close..............(305) 255-RTFM
Unless the host (that isn't close)......................pob 570-335
is busy, hung or dead....................................33257-0335

peter%ficc@uunet.uu.net (Peter da Silva) (11/13/89)

After all the exchanges are on NXX, and after we've used up the NXX
exchanges, then what's the plan? 8- or 9- digit local numbers, or
4-digit exchanges, or partitioning Zone 1, or what?

(Yes, I know this will take a while... maybe another 20 years)


`-_-' Peter da Silva <peter@ficc.uu.net> <peter@sugar.hackercorp.com>.
 'U`  --------------  +1 713 274 5180.
"*Real* wizards don't whine about how they paid their dues"
	-- Quentin Johnson quent@atanasoff.cs.iastate.edu

deej@bellcore.bellcore.com (David Lewis) (11/14/89)

In article <telecom-v09i0505m05@vector.dallas.tx.us>, smk@attunix.att.com
(S M Krieger) writes:

> I am looking at my home state of NJ: a second
> area code was created for NJ in 1958 (the 201/609 split), and now a
> third area code (the 201/908 split) is being created.  Since it
> probably won't be 30 years until the next split, and 30 years after
> that until the fourth split, there has to be a better way to
> "stabilize" our phone numbers.

I don't know; 30 years between changes sounds pretty "stable" to me...

Seriously: Even without addressing implementation issues (i.e., how
you make it work), there are questions surrounding an eight-digit
"phone number".

Like, where do you put the eighth number?  Is it part of the CO code
(NXX) or part of the station code (XXXX)?  The former multiplies by
ten the number of CO codes available in each LATA -- including LATAs
in places like Montana where you may not need more CO codes for 20
years.  The latter multiplies by ten the number of stations available
in each CO code -- again, including places where more station codes
may not be needed for twenty years.

In addition, a change to eight digit numbers is actually a change to
11 digit numbers, since no phone in North America is uniquely
identified by a seven digit number today, but instead by a ten digit
number.

NPA splits allow the increase of available numbers where needed, and
leave the rest of the numbering plan alone.  Which seems to me to be a
rather cost-effective way of going about it.

Disclaimer: Just because I work for Bellcore, which administrates the
North American Numbering Plan, doesn't mean I know the labrynthine
workings of the Numbering Plan Administration organization...


David G Lewis				...!bellcore!nvuxr!deej

			"If this is paradise, I wish I had a lawnmower."

fleming@apple.com (11/14/89)

smk@attunix.att.com (S M Krieger) writes:

>Based on the number of area code splits that have recently occurred or
>have been announced, I am wondering if the idea of just expanding our
>phone numbers to 8 digits is being considered?

Actually, I think this would cost several billion dollars more than it
is worth... in addition to the vast amount of equipment out there, the
3+4 format is permanently wired into my brain.  But if we're going to
go through the incredible pain and agony of converting to more
numbers, we shouldn't just stop at 8 digits.  Take numbers to 9
digits, giving a 100-fold expansion, and everyone could have the same
number as:

    Social Security number
    ZIP+4 code
    Phone number
    and so forth...

Additional lines, FAX machines, cellular phones, beepers, etc. could
be identified as two digit suffixes on the 9-digit "root" number.  The
same number could serve as driver's license ID, bank account number,
etc.  Phone numbers would follow individuals as they moved from city
to city.  And, in the famous scenario, if you get a "number has been
disconnected" intercept, the fellow is dead.

Make that several trillion dollars more than it is worth, and take all
the above with a grain of salt and many smileys.  But if someone (the
Japanese, perhaps?) ever builds a city on the moon, I hope they start
off with a rational personal ID system.

+--------------------------+-------------------------------------------+
|  Stephen Fleming         | My employer doesn't pay for this account. |
|  fleming@cup.portal.com  | In fact, my employer doesn't even know    |
|  CI$:   76354,3176       | I'm here!  Disclaimer enough for any      |
|  Voice: (703) 847-7058   | network-aware lawyer-types, I hope...     |
+--------------------------+-------------------------------------------+

goldstein@delni.enet.dec.com (11/15/89)

In article <telecom-v09i0508m05@vector.dallas.tx.us>, peter%ficc@uunet.uu.net
(Peter da Silva) writes...

>After all the exchanges are on NXX, and after we've used up the NXX
>exchanges, then what's the plan? 8- or 9- digit local numbers, or
>4-digit exchanges, or partitioning Zone 1, or what?

>(Yes, I know this will take a while... maybe another 20 years)

Actually, we're almost out of NXX codes.  So far unassigned I think I
recall it's down to 909, 410, 310, 210, 710, 810 and 910; the latter
are formerly TWX.  And a couple being recovered from Mexico.

The plan is that area codes will next be in the pattern NN0, such as
260, 460, etc.  (Those are the first two in the Blue Book
recommendation.)  Since those can be prefix codes anywhere, the entire
NANP area will need to use 1+ dialing to identify that an area code
(NOT a toll call) follows.  That point in time is called "time T" and
is scheduled for something like December, 1995, but I don't recall the
exact date.

In the interim, some "interchangeable" area codes (i.e., 486, 779) may
be assigned to non-local exchange ISDN users.  Since they're not used
for local calling, they won't be accessible from the POTS net, but
will be accessible from ISDN (with its fancier protocol).

     fred

Disclaimer:  This information is from my own memory; I attend T1S1 but
not T1S1.4 which advises Bellcore on the numbering plan.

essachs@ihlpb.att.com (Edward S Sachs) (11/15/89)

How about this as an alternative for local calling:

Split the area code (as in the recent 312/708 split here in the
Chicago area), but go to 8 digit local dialing for intra-LATA calls.
For example, if your number was (312) 555-1234 and is now (708)
555-1234, it would be dialable from anywhere within 312 or 708 as
8555-1234.

Numbers still within 312 would have a '2' prepended to them.  In other
words, phone numbers would remain 10 digits, but local dialing would
be the last 8 rather than the last 7.  This could even be extended to
those parts of the Chicago LATA that are in 815 and 219, and would
also work for other multi-area code areas, as long as the final digit
of the area codes are distinct and not 1 or 0.

			Ed Sachs
			AT&T Bell Laboratories, Naperville, IL
			att!ihlpb!essachs, e.s.sachs@att.com

deej@bellcore.bellcore.com (David Lewis) (11/16/89)

In article <telecom-v09i0508m05@vector.dallas.tx.us>, peter%ficc@uunet.uu.net
(Peter da Silva) writes:

> After all the exchanges are on NXX, and after we've used up the NXX
> exchanges, then what's the plan? 8- or 9- digit local numbers, or
> 4-digit exchanges, or partitioning Zone 1, or what?

I'm not sure I understand the question.  Each NPA (Numbering Plan Area
 -- area code) will, over time, move to interchangeable CO (Central
Office -- exchange) codes.  That increases the number of CO codes
available in each NPA.  When all the CO codes in an NPA are exhausted,
then you do an NPA split like Chicago's going through now, and NJ will
go through in '91.

In about 1995, the remaining NPA codes will also be exhausted.  The
plan then is to go to interchangeable NPA codes -- so that the syntax
for a phone number will be NXX-NXX-XXXX.  That will provide for 640
new NPA codes, whereas there are currently 152 available N{0/1}X NPA
codes available.  That should keep things quiet for some time,
considering there will be (approximately -- I haven't removed codes
like N00 and N11) 6.4x10^9, or 6.4 billion phone numbers available in
North America.

Interchangeable NPA codes will, alas, need to be implemented
simultaneously across North America.  Big bucks.


David G Lewis				...!bellcore!nvuxr!deej

			"If this is paradise, I wish I had a lawnmower."

lars@salt.acc.com (Lars J Poulsen) (11/17/89)

>In article <telecom-v09i0508m05@vector.dallas.tx.us>, peter%ficc@uunet.uu.net
>(Peter da Silva) writes:

>> After all the exchanges are on NXX, and after we've used up the NXX
>> exchanges, then what's the plan? 8- or 9- digit local numbers, or
>> 4-digit exchanges, or partitioning Zone 1, or what?

In article <telecom-v09i0514m02@vector.dallas.tx.us>,
	   nvuxr!deej@bellcore.bellcore.com (David Lewis) writes (in
	   response to a question from Peter da Silva):
>[Even after all NPA have switched to NXX exchange codes, the remaining
> NPA codes will be exhausted around 1995.] The
>plan then is to go to interchangeable NPA codes -- so that the syntax
>for a phone number will be NXX-NXX-XXXX.  That will provide for 640
>new NPA codes, whereas there are currently 152 available N{0/1}X NPA
>codes available.  That should keep things quiet for some time,
>considering there will be (approximately -- I haven't removed codes
>like N00 and N11) 6.4x10^9, or 6.4 billion phone numbers available in
>North America.

Can this be accommodated without taking the whole system to ESS ?  I
would expect that when this happens, you will ALWAYS need to dial the
area code, even for a local call. (Even though this may be handled by
your instrument by then).

/ Lars Poulsen <lars@salt.acc.com>   (800) 222-7308  or (805) 963-9431 ext 358
  ACC Customer Service              Affiliation stated for identification only
                My employer probably would not agree if he knew what I said !!

dave@uunet.uu.net (Dave Levenson) (11/19/89)

In article <telecom-v09i0518m09@vector.dallas.tx.us>, lars@salt.acc.com
(Lars J Poulsen) writes:

(... regarding interchangeable NPA codes...)

> Can this be accommodated without taking the whole system to ESS ?  I
> would expect that when this happens, you will ALWAYS need to dial the
> area code, even for a local call. (Even though this may be handled by
> your instrument by then).

No, you won't ALWAYS need an area code.  What you will ALWAYS need is
what you already need in some parts of the US: you'll need to dial a
leading 1 before an area code, and you'll never need a leading 1 for
intra-npa calls.


Dave Levenson                Voice: (201) 647 0900
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

deej@bellcore.bellcore.com (David Lewis) (11/20/89)

In article <telecom-v09i0518m09@vector.dallas.tx.us>, lars@salt.acc.com
(Lars J Poulsen) writes:

] In article <telecom-v09i0514m02@vector.dallas.tx.us>,
]    nvuxr!deej@bellcore.bellcore.com (David Lewis) writes (in
]    response to a question from Peter da Silva):
] >[Even after all NPA have switched to NXX exchange codes, the remaining
] > NPA codes will be exhausted around 1995.] The
] >plan then is to go to interchangeable NPA codes -- so that the syntax
] >for a phone number will be NXX-NXX-XXXX.  That will provide for 640
] >new NPA codes, whereas there are currently 152 available N{0/1}X NPA
] >codes available.  That should keep things quiet for some time,
] >considering there will be (approximately -- I haven't removed codes
] >like N00 and N11) 6.4x10^9, or 6.4 billion phone numbers available in
] >North America.

] Can this be accommodated without taking the whole system to ESS ?  I
] would expect that when this happens, you will ALWAYS need to dial the
] area code, even for a local call. (Even though this may be handled by
] your instrument by then).

Two questions here:

(1) Can interchangeable NPA codes be implemented without replacing SXS
and crossbar switches with ESS (stored-program control) switches?

(2) When interchangeable NPA codes are implemented, will you always
need an area code, even for a call in the same NPA?

Question 1 I honestly don't know the answer to, although I would
*suspect* the answer is "yes".  _Notes_ (*) talks around the subject
without coming out and saying it: "The cost of such conversion
[accepting NXX codes as NPA codes] is largely a function of the type
of switching systems involved.  For example, electromechanical systems
are generally more expensive to convert than electronic switching
systems.  The replacement of electromechanical switching systems will
have a favorable impact on the cost..."

For question 2, I can safely say the answer is "no".  I don't want to
quote two pages of text and two pages of tables (for those of you who
are interested, it's sections 3.03 to 3.13 and Tables 3-C and 3-D of
_Notes_...) to explain, but I'll try to summarize...

The recommended standard dialing procedure for NPAs which have
implemented interchangable CO codes, and for the NANP when the cutover
to interchangeable NPA codes takes place, is called the "prefix
method".

The prefix method "... is to have the callers provide a positive
indication of their intention by dialing '1' in front of the area code
on all 10-digit (and only 10-digit) calls."  In other words, 1+NXX
indicates that the NXX is an NPA code, and NXX alone indicates that
the NXX is a CO code in the same NPA.  Therefore, an area code is only
required, preceded by a '1', for calls outside the home NPA.

(*) Notes on the BOC Intra-LATA Networks -- 1986.  TR-NPL-000275, Issue
1, April 1986.  My favorite reference...

NPA  = Numbering Plan Area, or area code.
NANP = North American Numbering Plan
NXX  = NANP syntax for a three-digit string, {[2-9],[0-9],[0-9]}
CO   = Central Office.  In a phone number, e.g. 765-4321, 765 is the CO code.
ESS  = Electronic Switching System.  A switch in which the switch fabric
       is centrally controlled by a computer.
SXS  = Step by Step switch.

Anyone that doesn't know what BOC means hasn't been paying attention
for the past six years...


David G Lewis					...!bellcore!nvuxr!deej
	(@ Bellcore Navesink Research & Engineering Center)
			"If this is paradise, I wish I had a lawnmower."

jimmy@icjapan.uucp (Jim Gottlieb) (11/20/89)

In article <telecom-v09i0508m04@vector.dallas.tx.us> nvuxr!deej@bellcore.
bellcore.com (David Lewis) writes:

>there are questions surrounding an eight-digit "phone number".
>Like, where do you put the eighth number?  Is it part of the CO code
>(NXX) or part of the station code (XXXX)?

Here in Tokyo they have decided to go with 4-digit CO codes.
Presently, both 7-digit and 8-digit numbers (the 8-digit ones all
begin with '5') are being assigned.  The other day I spotted a
billboard as I was riding a streetcar.  It announced that as of 02:00
on Jan. 1, 1991, all telephone numbers in the area code of 03
(Tokyo-to inside the 23 ku) will change to 8 digits.  All 7-digit
numbers will have 3 prepended to them.  The sign showed "3XXX-XXXX".

However, Japan uses the European style of flexible area code and
number lengths so changing to 8-digit numbers in one area code will
not be a technical problem.  03-XXXX-XXXX will still be within the
maximum length of numbers allowed (Kawasaki-city is 044-NXX-XXXX).

On an unrelated subject, NTT has been running lots of ads lately
informing people that they no longer need to dial an area code to
reach Directory Assistance for numbers in other area codes.  Now, a
simple call to '104' can get you a number for any place in the
country.  I guess their DA is now computerized :-).

As far as whether the U.S.  should "bite the bullet" now and convert
to 8 digits, I would think it will be even easier in the future when
more and more of the country will be served out of SPC switches.

Jim Gottlieb 					Info Connections, Tokyo, Japan
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
       <jimmy@pic.ucla.edu> or <jimmy@denwa.uucp> or <attmail!denwa!jimmy>
Fax: (011)+81-3-239-7453           Voice Mail: (011)+81-3-944-6221 ID#82-42-424

cmoore@BRL.MIL (VLD/VMB) (11/21/89)

Dave Levenson <westmark!dave@uunet.uu.net> writes:
> (... regarding interchangeable NPA codes...)
> you'll never need a leading 1 for
> intra-npa calls.

Yes in New Jersey. But in Maryland and in area 703 in Virginia,
direct-dialed long-distance intra-NPA is 1+NPA+7D (had been NPA+7D
from the DC area, 1+7D elsewhere).  But leading 1 means that what
follows is area code (same as what New Jersey now has).

Delaware still has 1+7D for toll calls within it.  Presumably this
must change to 7D or 1+NPA+7D when N[0/1]X area codes run out.

I no longer recall where I saw this (N.Y.Times?), but there was some
mention in print of proposed borough code for calls within NYC.  This
was rejected, and you must instead use the area code on calls across
what be- came the 212/718 border.  I guess a reason to reject 8-digit
numbers is the problem of explaining it to people from outside the
area?

rmadison@euler.berkeley.edu (Linc Madison) (11/21/89)

In article <telecom-v09i0514m01@vector.dallas.tx.us> Ed Sachs writes:
>How about this as an alternative for local calling:

>[dial the last digit of area code + 7-digit # for local calls, for
> a total of 8 digits; e.g., (31)2-NXX-XXXX and (70)8-NXX-XXXX in the
> Chicago area.]

>This could even be extended to
>those parts of the Chicago LATA that are in 815 and 219, and would
>also work for other multi-area code areas, as long as the final digit
>of the area codes are distinct and not 1 or 0.

Interesting idea, but there are lots of areas where it wouldn't work,
such as here in the S.F. Bay Area (splitting 415 to add 510) and N.J.
(201) and Maryland (301).  Also, it seems to go against the grain of
the whole NANP.

Speaking of which, another message mentioned that you will not have to
dial the area code for calls within your NPA.  That's the Bellcore
recommendation, but Texas is an exception: within 214 (and 903 when it
comes into being, and 512 soon I'd guess) you must dial the area code
for all toll calls, even if it's the same.  In Texas, it has NEVER
been possible to dial any toll call without dialing 1 or 0.  So in
Texas, you will have to dial 11 digits for all long-distance calls
after Time T.

   Linc Madison   =   rmadison@euler.berkeley.edu