In message . li, at
00:32:35 on Mon, 20 Jul 2009, Tom Anderson
remarked:

There *is* an underlying technical issue, in that out-of-area codes
don't scale, because they involve running wires from one exchange to
the other.

My understanding is that there are already wires running from one
exchange to the other. That's how the phone calls get around, d'you see.

As others have pointed out, those "wires" are often fibre with many
calls MUXed together. And from a system architecture point of view they
are also "trunks", and not "subscriber lines", therefore not suitable
for a classic "wired in" out of area number.

Out-of-area numbers don't involve special wires. It's done with
software, in the routing layer. But it's not done terribly well, so
there is still a cost - cheaper than special wires, but more than zero.

Diverting the calls would make best use of the infrastructure.

Clive Feather gave a good explanation of this some time ago on this
group. From what i remember, everyone agrees that there's a sensible
way to do number porting that wouldn't require exchange Q to be
involved in a call from A to B just because B's number was once at Q,
but that's not how things work at the moment, and getting it changed is
going to be a painful process.

As painful as the process for getting a new scheme for numbers ported
from one telco to another, I expect. That's been dragging on for years.
--
Roland Perry