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

Owen DeLong owen at
Wed Apr 13 20:12:46 UTC 2016

> On Apr 13, 2016, at 12:45 , John R. Levine <johnl at> wrote:
>>> 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.
>> Would you agree that 408-921 is a geographic number?
> No.  It's a prefix, assigned to the at&t switch in west San Jose.
>> I guarantee you that there are phones within that prefix within US/Calif/LATA-1 and also some well outside of that, probably not even in the same country.
> Who said anything about phones?  Could you describe what "geographic numbers can be located to a switch" means to you?

I guarantee you that many, if not most at this point, of those numbers are no longer actually handled by that switch most of the time.

I suspect that there are more SS7 exceptions than default within that particular prefix which is why I chose it.


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