Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!decwrl!sun-barr!texsun!texbell!vector!telecom-gateway From: nvuxr!deej@bellcore.bellcore.com (David Lewis) Newsgroups: comp.dcom.telecom Subject: Re: Area Codes - a few comments Message-ID: Date: 25 May 89 18:21:51 GMT Sender: news@vector.Dallas.TX.US Organization: Bell Communications Research Lines: 64 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 176, message 5 of 8 In article , cowan@marob.masa.com (John Cowan) writes: > >[Moderator's Note: Why 411-611-911 are not used as area codes is pretty > >obvious, since they equal Information, Repair Bureau, and Emergency in > >that order. But why can't numbers like 210-310-311-511 be used? Or numbers > >like 410-510-710? They at least resemble area codes and would not be so > >confusing to a phone user. PT] > Historically, the N10 codes were used by TWX (otherwise Telex II); whether > this is still true, I don't know. AT&T set up TWX to compete with Telex, > and used a hitherto-empty part of its name space to avoid interference. > Later, AT&T had to sell off TWX, but the N10 codes are still treated as > sacred. The last time I checked into the matter, which was maybe 15 years > ago, my local telco (New Jersey Bell) treated some N10 codes as "invalid > exchange" and others as "invalid area code", kind of randomly. > [Moderator's Note: But some readers have maintained, very vigorously, that > since Western Union central offices are in no way connected with or wired > through Bell central offices, their use of those numbers have no longer > any bearing on area codes. I put those codes (410-510-610-710-810-910) in > the master list of numerical area codes message run several months > ago, and finally took them out. What is the definitive answer on this? Will > someone from Bellcore or some other authoritative source please reply? PT] According to "Notes on the BOC Intra-LATA Networks -- 1986", Bellcore TR-NPL-000275... 700, 800, 900, and 610 are SACs, or Service Access Codes, which are currently assigned. 610, as stated elsewhere, is assigned in Canada for TWX service and is not used in the BOCs; but, as numbering assignments are according to the North American Numbering Plan (NANP), not the US Numbering Plan, 610 is unavailable in the US. The other N00 codes (200-600) have been reserved for use as SACs and will not be assigned as NPAs. N11 codes are reserved for special functions. N10 codes (aha, he finally gets to it) are among the remaining legally assignable NPA codes. As of the publication of Notes, 19 codes of the N0/1X format were unassigned. These included the 5 reserved for SACs, leaving the 7 available N10 codes plus 7 N0/1N codes. I believe the N10 codes will be the last to be assigned as NPAs. Disclaimer: This is taken from the reference; I don't work in Numbering Plan Administration. As far as I know, though, the TR represents the most recent policy (although some NPAs have been assigned since then). -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= David G Lewis "If this is paradise, I wish I had a lawnmower." Bellcore 201-758-4099 Navesink Research and Engineering Center ...!bellcore!nvuxr!deej [Moderator's Note: Thank you for providing this information. I consider it an authoritative answer. Therefore, to those who have said otherwise, we are NOT 'running out of area codes' (we still have 7+2=9 left of the more or less conventional form). And I may be wrong, but I'll bet they hold 909 open until after the other 8 have been assigned, and Telenet will continue using it for switching calls in their network. PT]