Path: utzoo!attcan!uunet!ns-mx!ceres!dino!ux1.cso.uiuc.edu!uwm.edu!mailrus!accuvax.nwu.edu!nucsrl!telecom-request From: nvuxr!deej@bellcore.bellcore.com (David Lewis) Newsgroups: comp.dcom.telecom Subject: Re: Answer to Area Code Congestion Message-ID: <2807@accuvax.nwu.edu> Date: 11 Jan 90 18:31:04 GMT Sender: news@accuvax.nwu.edu Organization: Bellcore, Livingston, NJ Lines: 92 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 23, message 3 of 7 In article <2748@accuvax.nwu.edu>, U5434122@ucsvc.ucs.unimelb.edu.au writes: > Here is a way to ease area code congestion without being too difficult > to implement in North America. It basically means that the affected > area switches to 8 digit numbers without any other area needing to > know. Most telephone numbers stay the same, with the addition of > another digit, and for those that change, working out the new number > is very easy. > Taking Los Angeles area 213 as an example: > 1. Abolish area code 213 and in its place establish areas 225 and 228. > This will mean that all areas using 225 and 228 as prefixes must > remove 1+7D toll dialling. In effect, this means that all of the North American Numbering Plan must cutover to fully interchangeable codes. Although you restrict it to 225 and 228 at the start, you assume that farther down the line 22X is the next step, and 33X and other prefixes will be used in other areas. As time goes to infinity, the number of NPAs that have none of these prefixes assigned goes very, very rapidly to 0. Therefore, the entire NANP must cutover to fully interchangeable codes. This is, when it occurs around 1995, going to be *the* biggest and most expensive change to the NANP. > 2. There is no geographical isolation of 225 and 228. Instead, the > areas are assigned to the prefixes 2xx-5xx and 6xx-9xx. > 3. Old numbers beginning with 5 and 8 have their first digit changed > to 7 and 3 respectively. > 4. Dialling within the 225-228 area *must* begin with either a 5 or an > 8. Any attempt to dial a number beginning with 2,3,4,6,7,9 should be > directed a recorded message to remind about the new system. This > should last several months. Let me see if I understand this. The number that used to be 213-455-XXXX would now be 225-455-XXXX, but would be, within this NPA, dialed as 5-455-XXXX. From outside this NPA, it would be dialed 1-225-455-XXXX. Dialing within the NPA would be 8-digit; dialing to outside the NPA would be 11-digit (1+NPA+NXX-XXXX). > The benefits of this system are many, including the retention of LA as > a large community, and an inexhaustible supply of new prefixes, by > simply adding new pseudo-areas 22N when everyone was used to 8 digit > dialling. Here's a trap. You say above that, in a "pseudo-area" 2 2 5/8, CO codes can not begin with 5 or 8. So if you add "pseudo-areas" of the format 22N (I think you meant 22X -- N excludes 0/1, X doesn't), this restricts you from having CO codes beginning with N (X). Therefore, CO codes don't begin with any number (as CO codes cannot begin with 0 or 1). > Comments anyone?? Well, you asked for it. First, the implementation side. As mentioned above, this is not "easy to implement" -- it means cutting over the entire NANP to fully interchangeable codes. I've been trying to figure out how, exactly, to phrase the other problems I see with it -- the usability problems, as opposed to the implementation problems. I think what it comes down to is -- why bother screwing around with 8-digit dialing when we can go straight to 10-digit dialing, in a manner consistent with the current dialing syntax, continuing to provide 7-digit dialing for HNPA calls? The proposal here would: * Change on the order of 1.5M 7-digit phone numbers (all 5/8XX-XXXX numbers) * Change dialing syntax from 7-digit to 8-digit in some -- but not all -- NPAs, therefore removing the universality of HNPA dialing in the NANP (Now, in your home NPA, you dial 7 digits. In this proposal, in some home NPAs you dial 7 digits, in some you dial 8 digits.) * Provide less than an order of magnitude increase in available numbers, compared to more than two orders of magnitude increase by going to fully interchangeable codes * Not be any less expensive to implement than fully interchangeable codes. Maybe I'm missing something obvious, but this seems to present all the disadvantages of fully interchangeable codes, add new disadvantages of its own, and not provide any advantages... David G Lewis ...!bellcore!nvuxr!deej (@ Bellcore Navesink Research & Engineering Center) "If this is paradise, I wish I had a lawnmower."