On Sun, 17 Aug 2003 13:44:25 -0400, "Dr. Anthony J. Lomenzo"
wrote:

the phone system wires carry their own juice, well, even
those wires have to have a source for their power generation! Where is
it and note that even in extensive power grid failures like the nation
just experienced, the phones came through! So where is their source? Or
does the phone system commonly LOW DC voltage and thus absence of any
needed AC 'push' amperage [dunno, I'm asking!] permit a DC generator
system that can virtually run with no problems!? Any phone techs in the
house?

I used to work for ALLTEL, a medium sized Incumbent Local Exchange
Carrier, in the United States.

A telephone system's local loop in the United States, the two pair of
wires which connect to your home (only one of which is usually in use,
so the other might not be connected to the entire system) are wired to
a bank of batteries which provide +48vDC. There are generators which
keep the batteries charged, but the phone system powers its equipment
with the DC electricity from those batteries.

And, yes, as the price for maintaining that monopoly all those years,
AT&T was required to meet uptime standards and connect to anyone who
wanted the service, no matter where he lived. The result after several
decades was a remarkably complete and nearly ubiquitous telephone
system nationwide. The Babybells and the other ILEC companies which
survived them still have to meet those requirements. "Cable
telephone", IP telephony, and cell phone providers do not.

That's why the system glitches with "cable telephone" service, small
though they were, were so surprisingly significant to people; at least
two generations of Americans grew up without ever experiencing a
telephone infrastructure failure of any kind.

But, it's also why the "last mile" of high-speed Internet connectivity
has been so difficult to make ubiquitous. That nine-nines-reliable
phone network is only reliable for 3-minute-average telephone
conversations nationwide.

But it all held true until the Internet and cell phones came along,
and all the network provisioning assumptions the Bells made got shot
to gehenna when people nailed up their phone lines to have a 24/7
Internet connection and started to have three or more telephone
numbers per household. It was only then that we started hearing "we
can't do it" on a regular basis, and only then that the area codes
started to change a lot.

Over in Europe and in the "Third World" nations, they're still
building out a telephone network for their people, what with costs
having been so much higher and brain trust so much more expensive,
before some very recent political changes were made. That's why those
systems appear to be more advanced; the initial investments in network
infrastructure were made far later. The older infrastructure in North
America and (to a slightly lesser extent) Western Europe still works
just fine for what most people want.

Rob