----- "Karl Fife" <[EMAIL PROTECTED]> wrote: > Theory 1 > Is it all done with timeouts, but they're CONDITIONAL timeouts. > i.e. give a LONG timeout if the number: > -did not start with a 1 and is still shorter than 7 digits, > -started with a 1 and is still shorter than 11 digits > -started with a 011 and is shorter than the theoretical international > minimum lenght > > Theory 2 > As you know, a few years ago the 2nd digit of the NPA was always 1 or > 0. > Therefore the switch could easily determine(without the leading 1) > if > your first three digits were an NPA or just an NXX (exchange). They > were nationally unambiguous. Now that's no longer true. STILL, it > could be possible to consider all known valid NPA's and exchanges so > they > can determine via context what you're trying to do, and thereby > optimize > the dialing experience? > > Can anyone speak to this? I would very much appreciate any > knowledgable input.
Well, my input is knowledgeable, though not authoritative. Yes, each NANP switch actually does have a routing table loaded locally (they call them "translations") that tells it where to route calls for each and every valid NPA-NXX in the NANP, and this could be used to authenticate the first 3/6 digits of 7/10/11 digit dialled numbers for intra-NANP calls, and in fact, I would bet that you're correct that that's how they accomplish it. I have never actually seen live switch code on this, but I think I could locate some people who have -- but yes, you'll play hell duplicating it exactly on something with as small a brain as an ATA. Cheers, -- jra -- Jay R. Ashworth Baylink [EMAIL PROTECTED] Designer The Things I Think RFC 2100 Ashworth & Associates http://baylink.pitas.com '87 e24 St Petersburg FL USA http://photo.imageinc.us +1 727 647 1274 Those who cast the vote decide nothing. Those who count the vote decide everything. -- (Josef Stalin) _______________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- AstriCon 2008 - September 22 - 25 Phoenix, Arizona Register Now: http://www.astricon.net asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users