micky wrote:


But what about FIOS. If there is a power failure at the exchange, do
they all have generators? Are there amps or something on phone poles
between the telephone exchange and my house that depend on a source of
power that's neither the exchange or my house?
There is no "exchange" anymore, in the way there used to be these
central offices with a #5 ESS or whatever. It is all moving to ATM
backbone, which is essentially an internet backbone. They put
RT's in the neighborhood that are hooked to a fiber, and branch out
copper cable to the neighborhood. So, the switches are several hundred to
a thousand or so subscriber lines, and distributed all over the landscape,
instead of one building per town. If you drive around, you'll see these
boxes all over the place. There are usually 3 boxes, the RT unit itself,
a power entry module with an electric meter on it, and a wire cabinet.

We have Charter cable here as the only alternative to DSL (which doesn't
work well in our region due to the crappy phone cables) and they have
somewhere around 8 hours of batteries in each box, which serves a couple
blocks. When they have an extended outage, you see them bring out a
little gas generator to each pole with the Charter Pipeline box. Must
be a big pain to set up all those generators.

I can't answer to FIOS, but I'm sure there have to be neighborhood
concentrators, as they can't possibly run miles of fiber to EACH residence.
Fiber has insane capacity, so they can concentrate traffic for hundreds
of high-speed service customers onto one fiber. And, I'm sure those
concentrators only have so much backup battery capacity.

Jon