Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!elroy.jpl.nasa.gov!lll-winken!telecom-request From: Dave.Leibold@f135.n82.z89.onebdos.UUCP (Dave Leibold) Newsgroups: comp.dcom.telecom Subject: Re: Billing Question Message-ID: Date: 20 Jun 91 05:38:00 GMT Sender: Telecom@eecs.nwu.edu Reply-To: dleibold@attmail.com Organization: TELECOM Digest Lines: 40 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 482, Message 5 of 9 Leroy Donnelly writes: > Could someone give me insight on how the phone companies bill for long > distance. Is it based on a grid map or LAT/LONG points. Each exchange or "rate center" is given what's known as a V&H co-ordinate representing Latitude and Longitude. For instance, Toronto Ontario has a V of 4981 and an H of 2488. For a rate distance between two points, the difference in V's of the points and the difference in H's of the points are squared and added, much like the Pythagoreas Theorem used to calculate the hypotenuse of a triangle. If rate distance is R, then R^2 = V^2 + H^2, although the R value won't exactly come out in miles or kilometres. A bit of extra calculation is done, but the principle is there. Those in Bell Canada territory can try to find CRTC tariff 6716 for a detailed look at the calculation, or other telco long distance tariffs might explain this. There's also supposed to be an AT&T Tariff FCC #10 which i've never seen, but is referred to in Bell Canada's tariff. I also caught the V&H co-ordinates in a book entitled DDRG (Direct Dialing Rate Guide?) complete with stuff like Mexico's 52X and 8XX pseudo-NPA's listed. That document might merely be a hardcopy version of the Bellcore V&H tape spoken of frequently in the Digest. There were even things called "coin check" digits which refer to the digit of the local number just after the prefix. For instance, a coin check digit of "9" for a prefix 234 would mean that operators have to be careful about placing collect calls to numbers of the form 234-9xxx. This is not too convenient for very small exchanges like 519-526; that prefix barely contains 300 phones, thus the coin check of 526-7xxx would mean all collect calls to 526 get the third degree (unless specific payphone series or numbers are now made available to operators electronically). dleibold@attmail.com Dave Leibold - via IMEx node 89:681/1 Dave.Leibold@f135.n82.z89.onebdos.UUCP