phone fun, was GeoIP database issues and the real world consequences

John Levine johnl at
Wed Apr 13 19:15:50 UTC 2016

>> Actually, it's probably both US and Canadian.  When you call an 8xx
>> toll free number, the switch uses a database to route the call to
>> whatever carrier handles it, who can then do whatever they want.  The
>> provider for that number, Callture, is in Ontario but they can
>> terminate the calls anywhere, and send each call to a different place.
>I was careful to pick a number on a Canadian company's website.

Doesn't matter.  In the NANP, toll free 8xx numbers are routed by
carrier, not by geography, and it looks like this company handles
traffic in the US, too.  It's entirely possible that when you call
that number during the day you get someone in Toronto, and when you
call it at night, you get an answering service in the Phillipines.

>> Also, in fairness, the US is about 90% of the NANP, so guessing that
>> an 8XX number is in the US is usually correct.
>That's another way of saying that it's deliberately wrong 10% of the
>time for pan-NANP prefixes. Better to say "I don't know" than to just

Really, they're not assigned to locations, they're assigned to
carriers.  They can even be assigned to different carriers in
different countries although that's not common.

More to the point, saying "somewhere in the US", even if it's
occasionally wrong, will not send nitwits with guns to a particular
location.  NANP geographical numbers can be located to a switch (give
or take number portability within a LATA), but non-geographic numbers
can really go anywhere.  On the third hand, it's still true that the
large majority of them are in the U.S.


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