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

John R. Levine johnl at
Fri Apr 15 14:51:45 UTC 2016

> So maybe 10% of all cell phones are primarly used in the "wrong" area?

> Out of curiosity, does anyone have a good pointer to the history of
> how / why US mobile ended up in the same numbering plan as fixed-line?

The US and most of the rest of North America have a fixed length
numbering plan designed in the 1940s by the Bell System.  They offered
it to the CCITT which for political and technical reasons decided to
do something else.  (So when anyone complains that the NANP is
"non-standard", you had your chance.)  Fixed length numbers allowed
much more sophisticated call routing with mechanical switches than
variable length did.

For reasons not worth rehashing, there was no possibility whatsoever
of adding digits or otherwise changing the numbering plan.  So if they
were going to do caller pays mobile, they'd need to overlay mobile
area codes on top of existing codes, and there weren't enough spare
codes to do that.

Putting mobiles into a handful of non-geographic codes as they do in
Europe wouldn't work because the US is a very large country, long
distance costs and charges were important, and they needed to be able
to charge more for a mobile call across the country than across the
street.  (The distance from Seattle to Miami or Boston to San
Francisco is greater than Lisbon to Moscow or Paris to Teheran.)  In
the US, mobile long distance charges have mostly gone away, but my
Canadian mobile still charges more for a call to a different province
than one to the same city.

So rather than doing caller-pays as in Europe, North America does
mobile-pays, with the mobile user charged for both incoming and
outgoing calls.  There turn out to be good economic reasons for that
-- European mobile users imagine that incoming calls are "free",
but in fact they are very expensive to the caller because the
caller has no say in choosing the carrier or the price.  For all
its faults, the competition in US mobile service drove down prices
much faster than in Europe, and US users use more minutes/month
than Europeans do.  If you want me to call you in the UK,
I'm happy to call your landline for 1.3c/min, not so happy to
call your mobile at 26c/min.

ObNanog: E.164 and VoIP don't make this any easier.


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