Why maintain the NANP?

Mostly inertia, but also for economic reasons. There are countries that would love to join the NANP; Guyana, for example.

They could saddle us with 3-digit codes here in the US and Canada; it is, after all, official ITU policy that no further 2-digit codes will be allocated.

From the technical standpoint, it would be an enormous expense for very little benefit -- rather like the idea of splitting the 415 area code again, given that 80% of all the numbers in the current 415 are in the same rate center, SF Central. The US would gain inconsequential extra numbering space. Canada and the others would lose the cachet of being "1+" instead of "011+".

On the user side, it would be a tremendous benefit to know that you're not dialing some random Caribbean island when you think you're calling Virginia, but the rate disparities continue to drop. Also, the people outside the US would fight you, so there would be a considerable political/diplomatic cost involved as well.

The bottom line is that the system ain't broke enough yet to be worth fixin'.

Convenience. *GRIN*

seriously, though that's the case. Any geographic split at the country code level would add an additional 5 digits to US to "non-US, former NANP" destinations.

Look at the distribution of NPAs. Reclaiming the rest of the NANP space for domestic US use wouldn't buy a lot of additional time.

One "country code" for 'East of the Mississippi', and another one for 'West of...' _would_ provide a significant additional life for 10-digit numbering, but I rather doubt that -that- would be politically acceptable to the U.S.

Of course, simply migrating to 4-digit NPAs results in 5 times more expansion space.

AND which can be phased in relatively painlessly. Start by mapping all the existing NPAs to 'XXX0', with permissive dialing in either XXX or XXX0 form. Add an 'advisory' message when a non XXX0 form is used that they should start using XXX0 for the NPA.

After a reasonable period -- 2 years, maybe -- make the 4-digit NPA mandatory with intercepts (reminding of 4-digit NPAs) on all the XXX[2-9] NPAs. One can start allocating XXX1 NPAs at this point.

LONG before XXX1 is depleted, one can pull the reminder intercepts, and start allocate from XXX[2-9], _if_ there is good reason to do so.

I had a simply solution some years back which I sent to the proper authorities: Add 1 digit to the subscriber line numbers. All modern switches can accommodate this, and it multiplies the available numbers

10-fold. Give the existing phone numbers a 0 at the end and then switch over some Sunday morning.

But nobody listened to me.

Not surprising, since your proposal is utterly impractical. The biggest problem is the idea that the entire country could cut over from one dialing plan to another in a gigantic flash cut. That ain't gonna happen.

Whatever path they do use has to have a permissive period to debug and upgrade all the equipment that knows about phone numbers, which is a heck of a lot of stuff beyond CO switches. Most of the digit patterns in the NANP are allocated, so there's not a lot of ways to do permissive dialing. The two I've seen are to expand the area code by inserting a 9 between the first two digits of the area code (no N9X area codes have been assigned), expand the local number by inserting a

0 or 1 in front of the existing seven digits, or most likely both. So

NXX-NXX-XXXX -> N9XX-0NXX-XXXX

The N9XX change can be done without changing existing dialing plans, since there's no N9X area codes.

The 0NXX change would require everyone to dial the full number, getting rid of 7D dialing within NPAs. That will encounter some resistance from areas like mine which have 7D dialing (even for intra-NPA toll calls, which is fine with us) and won't see any benefit from dialing more digits for local calls.

R's, John

The California Public Utilities Commission had brought that up years ago and were told even though most switches could handle that they were told it was not practical because there were still small switches that could not handle the changes and would be that way for years to come, and I believe there are still many around. Besides doing that would effect the whole world. I know in many countries they have 4 and 4 numbers.

i am not from NA, so this doesnt directly affect me, but this statement is wrong.

This is what the UK did several years ago (the move was from 10 digit numbers starting "0" to 11).

so - by definition not utterly impractical since something like it has been done........

Actually, no, not at all. phONEday was not "a gigantic flash cut"; there was a significant period of parallel running (permissive dialing, in American terms).

Also, your comment ignores fundamental differences in the telephone routing systems in Europe and North America. It is significantly easier to add digits in the European scheme than in the North American scheme.

In sum, it is indeed "utterly impractical" to "simply" add a digit to every line number in North America. When the time comes to add one or more digits to the current NANP, it will require years of planning and billions upon billions of dollars.

In article Linc Madison writes: > In article , stephen > wrote: ... > > > Not surprising, since your proposal is utterly impractical. The > > > biggest problem is the idea that the entire country could cut over > > > from one dialing plan to another in a gigantic flash cut. That ain't > > > gonna happen. ... > > This is what the UK did several years ago (the move was from 10 digit > > numbers starting "0" to 11). > >

> > > > so - by definition not utterly impractical since something like it > > has been done........ > > Actually, no, not at all. phONEday was not "a gigantic flash cut"; > there was a significant period of parallel running (permissive dialing, > in American terms).

The "gigantic flash cut" has been performed once (a long time ago) in Belgium. At midnight, some area codes received an additional digit, and in other area codes all numbers obtained an additional digit. So all country-wide telephone numbers changed from 8 (2 + 6 or 3 + 5) to 9 (2 + 7 or 3 + 6) digits. No permissive dialling afterwards. You could not use your phone from a few minutes before the switch to a few minutes after the switch. I think it has been some 40 years ago.

I do not think that was the case when Belgium switched over, all switches were still mechanical at that time, so it required a lot of additional switching apparatus that would not be used before the change, but would come in use after the change.

It was and it still is. The signalling system that phone systems use in Europe is designed for variable length numbers, but the one in the NANP knows that all numbers are 3+7 digits long.

They may well have had to add extra equipment to upgrade individual switches, but they didn't have the change the way that all the inter-switch trunks work.

It has been a while, 11 years, but I seem to remember that the SS7 could handle extra digits, so inter office trunks should work fine. It is just a cost factor and getting people used to using larger phone numbers, I remember when we cut GTE's Edgemont CO to 53A (ya Step) to seven digit it took years to get people to dial right, repair was getting calls for months by customers that could not reach numbers they had dialed for years with just 5 digits to use 7 digits and whe nthe 1 plus came into use it was even worse.

> >

I think that ARS would be impacted in the U.S. When I recall the challenges of managing the translations and routes on a small PBX I can imagine how nightmarish it would be.

But here's the thing, flip one little variable on that PBX I managed (It was an Avaya Prologix) and it became a European switch, with flexible numbering and all.

So it's not that the switches can't do it, it's just that managing things like route selection, etc. would get a bit sticky.

Modern digital switching should be able to handle it since it's all port based anyhow.

> >

Thrice, at least. Denmark and Norway did such changeovers somewhat less than 20 years ago. Going from E.162 style numbering plans ((05) 272214) to an ecma variety without area codes, (55272214 ). Cut in the early morning of january one year in the early nineties.

I sent a hands-on report to this very newsgroup the same day. Go google for it.

They phased out all the old mechanical pbx'es before these switches, or they made them work as dumb front-end muxes for the intelligence further into the network.

-- mrr