Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!rutgers!texbell!vector!telecom-gateway From: nvuxr!deej@bellcore.bellcore.com (David Lewis) Newsgroups: comp.dcom.telecom Subject: Re: 8-Digit Phone Numbers vs. More Area Codes Message-ID: Date: 15 Nov 89 16:26:36 GMT Sender: news@vector.Dallas.TX.US Organization: Bellcore, Livingston, NJ Lines: 30 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 514, message 2 of 11 In article , 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."