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In North America, phone numbers are always in the form NXX-NXX-XXXX, with N being a digit from 2-9 and X being a digit from 0-9.
Instead of 10,000,000,000 permutations, you only have 6,400,000,000
It is called NANPA and there are a few other reserved numbers mixed in (for example, in an NXX group, both Xs can not be 1 to avoid confusion with N11 services such as 911).
Wikipedia also has a good article about this.

I did something similar with javascript a few years ago. The javascript is used to codify the RFC BNF, which then generates the regex.

http://www.digitalxen.net/files/emailValidation.js

The other one was a regex for validating phone numbers (at least in the US). It was based on standards from NANPA and ATIX. It worked great until a phone company "accidently" started issuing numbers using one of the exchange codes set aside for testing.

http://www.digitalxen.net/files/phoneValidation.js

Because they're running out of numbers, and need to use every one they can.

Wikipedia.

North American Numbering Plan Administration.

The problem in the US is that area codes are assigned by http://www.nanpa.com/ who receives its direction from the FCC and the telecom industry of the US and other particpating countries. When I inquired about this many years ago I was informed that the FCC or a court had ruled that area codes CANNOT be assigned by technology (i.e. cell, pager, fax, etc.) because this is in essence telecom discrimination.

You are comparing two totally different numbering systems. Denmark has 8 digits for the subscriber. The NANP uses 7. Denmark has a population of 5,397,640. North America, plus the Carribean, roughly 334,700,000. New York City has a greater population than Denmark. Many states require two area codes just because of their population.

Also, Denmark has it's own country code, +45. North America has it's own. Denmark is responsible for it's own numbering plan. NANPA looks after all of North America and the Carribean.

Check the NANPA for more information on North American phone numbering.

What happens to your phone number when you move out of Denmark? Had you said that you could keep your number if you moved anywhere in the EU that would have been intersting indeed.

Yeah, it's US-centric, which is why it's done by a Canadian on a Canadian site.

With respect to telephone numbers, Canada is the fifty-first state, as USA and Canada are in the same numbering space. NANPA, whose name is the Toki Pona word for "number", is the name of an agency run by NeuStar that administers the area codes used for telephone numbers in Anglo-Francophone North America.

How do Slashdot readers make international phone calls?

For countries within the North American Numbering Plan, I dial "1" + area code + local number. For other countries, I dial "011" + country code + local number. It's pretty simple, eh.

the United States and its territories, Canada, Bermuda, Anguilla, Antigua & Barbuda, the Bahamas, Barbados, the British Virgin Islands, the Cayman Islands, Dominica, the Dominican Republic, Grenada, Jamaica, Montserrat, St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines, Trinidad and Tobago, and Turks & Caicos.

Credit card companies and toll-free numbers use ANI (automatic number identification) which cannot be easily spoofed.

Cingular should allow you to dial 7 digits to numbers in your area code in LA ... the dial plans for the area allow it. AT&T Wireless follows the dial plans as specified at the NANPA http://nanpa.com/area_codes/index.html ... do a search for your area code to see the allowed dial patterns.

A lot of other areas are moving to a forced 10 digit pattern because they are doing area code overlays of a physical area. LA has been doing splits of areas when introducing a new NPA. The 7 digit dialing is almost always retained when this happens.

I'm an employee on the AT&T side of this merger and this is something that will have to be fixed relatively soon. Our customers scream bloody murder if their 7 digit dialing breaks for any reason ... so I doubt that it's going away. My hopes are that it'll come to a Cingular network near you.

I'll get back to you on whether I welcome my new Cingular overloards ...

You don't honestly think some underpaid kids in Hyderabad are sitting there wearing out their thumbs actually sending a text message from a cell phone, do you?

You can send text messages through an e-mail gateway. 9175551212@yourcarrier.net, 9175551213@yourcarrier.net -- and since certain blocks of telephone numbers are reserved to cell phone carriers, and the assignments are published by The North American Numbering Plan Administrator, you can text 917555nnnn@yourcarrier.net and get probably 8500 successes out of 10000 e-mails sent.

There is no charge to send e-mail to a cell phone for the sender -- the receiver pays for it.

This is very much like phone number portability. The clue problem seems to be a general misunderstanding of what a hack the Local Number Portablility (LNP) process is. It is the equivelent of having an exceptions table that the router looks at before routing a number. Everything works as normal unless the number is an exception, then it handles it differently. Works fine when only a small percentage of the traffic is ported. Won't scale if everyone wants it. Oh, and it costs a fortune to maintain this hack (thus the LNP surcharge you pay every month).

In the telephone world each block of numbers is purchase by the carrier from NeuStar, Inc. They are the "Verisign" of the North American Numbering Plan, a position they won as a government contract after it was taken from BellCore (now Telcordia).

Each block of numbers is assigned to a specific switch. When you call one of those numbers it will always be routed to that switch. The switch has an exceptions table. Every incoming call is checked against the exceptions table. Calls that have been ported to another carrier are "traslated" and sent out to the other carrier for delivery to the customer. You can port your number but it will always run through the original carrier's switch.

555 numbers are already assignable. Check out the 555 master list for the numbers currently in use.

555 numbers are already assignable. Check out the 555 master list for the numbers currently in use.

Some (liekly most) of the false records are OBVIOUS. Like one which had 314-411-0000.

Note, prefixes of the form N11 are never valid. Since those are used for special services (and it is now defined for all N from 2 to 9, btw, see the North American Numbering Plan Administration page for details.)

Actually the numbers don't belong to the businesses. All numbers are handed out in North America by the North American Numbering Plan Administration in coordination with local regulatory agencies.

To allow businesses to compete on something that isn't their property is definitely ludicrous.

>Yes.

> NANPA

Thank you! (What do you know... an informative AC post. ;)

NANPA

The critical thing to understand with ENUM is that it mirrors the existing phone number hierarchy, beginning at the country code level. Consequently, the same entities that handle phone numbers, beginning with the ITU and ending with your local telco, are the same entities that have the authority to approve delegations within the ENUM (e164.arpa) domain.

The mention of Neustar in the article, whilst not explicit, is for Neustar to handle further delegations within 1.e164.arpa. But why should Neustar handle 1.e164.arpa anyway? Well, Neustar is the company that is currently entrusted with the NANPA (North American Numbering Plan Administration), which is the entity that the ITU has recognised as handling phone country code '1'. Obviously, it makes sense for Neustar to also handle this, and you'd think that it wasn't a big deal.

Curiously, it was enough of a deal for the US Government to formally request that the ITU or the RIPE NCC not delegate 1.e164.arpa to any entity back in April 2002. So at the present time, as the ITU hasn't received any requests to delegate 1.e164.arpa, the RIPE NCC hasn't created the delegation. Hence the original article trying to raise awareness of enum to 'merkins.

I wouldn't hold my breath for Nov 24th. There's a significant number of techinical issues that have yet to be worked out, that the FCC has conviently ignored.

Can the wireless carriers implement number portability? Yes... Will it break a bunch of a stuff if they do? Yes again.

One of the most significant things that still has to be addressed is exactly how, who, and when the PSAP databases get updated. For those of you not up on telco terminology, the PSAP database is what 911 uses to locate you by your caller-id info.

Of course, the major issue with the carriers has to do with increased billing costs. Each carrier (wirelines and wireless) has their areas divided into rate centers. These are typically, but not always, associated with NPA-NXX numbers. Visit NANPA for more info on NPA-NXX.

Moving numbers between carriers will mess with the rate centers severely, for awhile anyway, and cause much confusion between carriers in relation to call termination charges, etc.

I researched this a year ago when working out a fake number to use in a book, and finally have the opportunity to share this worthless information...

Through various resources such as CO code lists you can see which NPA-NXX are in use. I also considered writing a script to just register them all. It would have done the country a favor and been quite interesting.

Umm... We use the same phone number format in Canada. It is also used in Bermuda, and many Caribbean nations, including Anguilla, Antigua & Barbuda, Bahamas, Barbados, British Virgin Islands, Cayman Islands, Dominica, Dominican Republic, Grenada, Jamaica, Montserrat, St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines, Trinidad and Tobago, and Turks & Caicos. Since there is nothing in his post to indicate that Byron was in the States. You need to broaden your area code list, because it is missing a few:

242 Bahamas
902 Nova Scotia

also missing:
432 Texas
682 Texas
772 Florida
862 New Jersey

572 and 622 are reserved for future use, so don't bother with them.

So how'd you get that impossible number?

Take at look at the North American Numbering Plan Administration website as linked to in the write-up, there's alot of interesting information there.

They don't - the NY Times is proving once again how damned clueless they are.

There are NO local exchanges that begin with a '1', and there are no NPA ('area codes') that begin with a '1'.

What the NY Times doesn't understand is that 10 digit dialling is becoming more pervasive every month - it's required in Hotlanta (as Slashdot readers will notice), Toronto, Broward County Florida, Miami-Dade County Florida, the greater Washington DC area, Dallas, Houston, etc., etc.

I'm sure their reporter was just too bloody lazy to check the facts out at http://www.nanpa.com

So, go ahead and throw a '1' in front - the system will get a chuckle out of it.

(Side note: It got really interesting for a few months when Australia had 'normalized' its phone system, but before expanding it to have 8 digit local phone numbers. Someone misdialling could have hit either central Minnesota 1-612-555-1212 or New South Wales +61-2-555-1212. Luckily, it takes a '011' to get to Australia from North America and a '0011' to get from Australia to North America :-)

Actually 917 overlaps all 5 boroughs:
See map

And when I lived there this summer, more and more people were abandoning their landlines completely and just using their cell phones w/the built-in caller ID. Really doesn't matter how long the number is after you've typed it correctly once. You just call the person once and they save it in their contact lists. Plus when you're only there for 3 months, who wants to pay a $55 line activation fee + $30-something a month on top of the cell phone bill you're already paying?

I wasn't aware of 445 and 835. (I am in 215/267.) When was this announced, or are you in-the-know?

I wasn't aware of 445 and 835. (I am in 215/267.) When was this announced, or are you in-the-know?

Neustar is the same people who run NANPA.

Close, FCC controls / owns for US. NAMPA reports to them. Can you use the word "contract".

Just look and see:
Look here
The following was pulled from a notice

The Telecommunications Act of 1996 gives the Federal Communications Commission (Commission) exclusive jurisdiction over the North American Numbering Plan (NANP) in the United States, but permits the Commission to delegate any portion of that jurisdiction to state regulatory commissions or other entities. The Commission, recognizing that state commissions are uniquely positioned to understand local conditions and what effect new area codes will have on those conditions, has authorized the states to resolve many matters involving the implementation of new area codes, subject to the Commission's guidelines and rules governing administration of telephone numbers.

It is a well known fact in the world of human-computer interaction research that you should not present more than 7 or 8 items at once to a user, since that is the maximum amount they can absorb at one time.

It is a well-known bogus fact.

The original paper that started this 'magic number 7' superstition specifically addressed working memory capacity. People don't need to remember menus, because they're right there in front of them, so memory limitations don't apply.

This is why U.S. phone numbers are 7 digits--not counting the area code--for example.

No, it isn't. The original paper that introduced the notion of working memory being limited to about seven things at a time was published in 1956. The existing U.S. phone number scheme was developed nine years earlier, so its designers could not have used the memory research to inform their decision.

See here for more info:
Summary article on number seven misuse in UI design
Original magic seven paper
Phone number history

The FCC ruled out separate area codes for services such as cell phones and pagers. It would have been biased against new companies getting into those markets. The traditional local telephone monopoly would have gotten to keep the old familiar area code while the competitors would have been stuck with the strange new code.

For the authoritative site on area code issues, see the North American Numbering Plan Administration.

Calum

So who was making the fuss? Any legitimate reason other than "I don't like it"?

First off, it ain't just the people who have to learn to use the new numbers. It implies the need to update all the auto-dialing devices like alarm systems, speed dial numbers, ISP's numbers for modems, and fax machines. Yet, this isn't the whole of it.

These 10-digit phone numbers have to be processed by telecom switches to make the calls go through. Check out: North American numbering Plan Administration for the latest news about proposed changes and their implementations. As others have pointed out, there were choices made at the outset about the formatting of telephone numbers that permitted the switches to make optimizations in processing the number - as it was being dialed. For example: Starts with a '2'? Then it can't be long distance. Check the local NXXs that start with a '2'.

There is also the concept of permissive dialing. Even though it's NOT REQUIRED to dial the area code, I've long looked forward to being able to put in the whole telephone number (e.g. 1-212-345-6789) in my laptop's list of ISP's telephone numbers, and let the telco sort things out.

Once the people had grown accustomed to using 10-digit numbers everywhere, then it would make sense to me to change from PERMISSIVE 10-digit dialing to MANDATORY.

There are web sites and newsgroups dedicated to telephony (teh-LEF-oh-knee). Here's a newsgroup that I've found helpful: "comp.dcom.telecom" There's also a whole slew of useful sites accessible from google's telephony area.

But the big problem is that the FCC wants to make the option to have area codes that start with 0 or 1. See here for my explanation why this is bad.

And is it just me, or does it seem like the FCC is going into this without thinking about how the telephone system works at all? It seems like this would be better handled by a group that does this full time, the North American Numbering Plan Administration.

By the way, the terminology for this is Preferred Interexchange Carrier or PIC (pronounced "pick"). The "lock" you refer to is called a "PIC freeze". I agree, everyone should get one.

Without a PIC freeze, any carrier can submit a request to the phone company to change your PIC to them, which is convenient--unless they do it without your permission. If everyone had a PIC freeze by default those $90 checks you get wouldn't work because you'd still have to call the phone company to change the PIC.

MORE INFO: You can dial your PIC directly, look at this list (sorry, it's a zip file) for all of the codes. Many carriers have dozens of codes, they may or may not be equivalent to the carrier who recieves charges from the phone company.

When you call to change your PIC, they set your PIC to the number you give them or the carrier has told them to use.

To change your long distance carrier, you can simply tell your phone company to change the PIC (costs ~$5, which carriers sometimes pay for you if you let them change it). If you set up an account with that carrier, they can bill you directly or they will have the phone company bill you on the local phone bill, depends on the carrier and your preference. If you don't set up an account with them, you can get charged inordinate amounts (like $.50 a minute).

In March we changed our local business service (in Indianapolis) from Ameritech to Intermedia. Intermedia has done a wonderful job (I won't get into how Ameritech screwed up the cutover for 2 months). Ameritech, who was billing us for MCI long distance (who was the correct PIC), set up a new account with MCI the second we cancelled our Ameritech service (we already had a corporate account with MCI, but they didn't ask us). The result was that MCI billed us a minimum amount each month on a seperate bill which was payed by our Accounts Payable department without asking us.

I hang out at NANPA too, www.nanpa.com. I'm such a geek that I'd rather download area code maps than try to get a date!

Ya callin me a liar? :) Check out the official area code list, by the NANPA (the people who actually assign the area codes). It's probably just a new AC.