Check in ...East Coast BLACKOUT

In article , Roy Smith wrote:

In addition, central offices and other switching facilities have
emergency backup generators. As soon as the commercial power goes down,
the generators are supposed to crank up and keep things going for as
long as the diesel fuel holds out.

Yup. I used to work in a central office (CO) building until earlier this
year. It was grand! The worst complaint we'd have is a momentary brownout
affecting the computer room power about once a year or so -- we have
certain machines that are ultra-sensitive to brownouts and logs unique
error (but easily identified) messages without loss of functionality
whenever a brownout occurs, so that's how we know.

But other than that, it just... works. In fact, the CO power people runs a
full test of their building (commercial) / UPS (we're talking *industrial*
sized UPS systems, not the kind you buy in stores -- I've seen a power guy
literally hanging off a crowbar with all of his 250 pounds trying to remove
a large electrical circuit for power work in the basement of the CO during
a 1am maintenance!) / cutover strategies.

Usually scheduled as a midnight-4am maintenance window... they spend the
first hour going through the whole building, room by room (I've been there
once or twice when it happens) to make sure all occupants are safely out or
have working emergency gear (eg flashlights) and knows the exact 'escape
route'. I can say that it is *very* different walking around in a
completely dark building even when you know the exact steps by heart! Then
with the flip of a switch, most of the building goes dark. Rooms (eg
computer room, switch room, rooms with MDFs, etc) on the internal UPS power
stays alive. So no interruption in phone or data services. Only
interruption is mostly with lights / computers of offices in building,
which is mostly why they do it off-hours. (The call center is also on the
UPS if I recall.)

They then run whatever individual tests they like. Doesn't take long. By
3am at the latest, they start restoring commercial power to various
circuits in a controlled and staggered fashion. Also, twice a year they run
a smaller scale version of that power cutover test to building UPS power
during a work day and hours, and nobody notices a thing when it *does*
happen (also been there then, too). Not even a flicker.

I've heard of other telcos including a competitor in town doing similar
sorts of full-scale tests every 6 to 12 months. It helps people spot issues
in the procedures, and keeps people current on how to respond.

That's a far cry from many (most?) places in general (non-telco) that may
have alternative sources of power but *don't* regularly actually _verify_
things are still good, before the need pops up for real in an emergency.

I've seen the huge diesel generator in the basement. I think I once heard
that the CO in question was required to ensure they had at least a 14 day
supply in case of serious emergency (which would also include blackouts --
typically due to ice storms, which is a familiar phenomenon in this part of
country).

(Presumably, by the end of 14 day window, there would be a way to ship in
additional diesel fuel, to keep going on... indefinitely -- as long as fuel
delivery can be guaranteed, until commercial power is back. COs are pretty
high on the list of places to get power restored due to public safety
considerations.)

So I don't usually worry about dialtone for landline phones in case of an
emergency. (The system is not perfect, and it *is* indeed possible to
lose that service as experience and human nature / fickle nature of Murphy
has shown us, but on the whole, it's pretty well designed and robust.)

-Dan

(For the big blackout of 2003 affecting the east: I was out at home from
4:11pm until about 11:15pm when my home router came back; I was at work
bringing systems back up carefully once power was restored and didn't get
home until 4:30am with last report written and sent at 6am. That night
sucked! Fire crew came by at work because of flooding in data center due to
sump pumps NOT being on the data center UPS supply and they were afraid of
arcing and other concerns... we quickly had that rewired in record time!)

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

"Robert Perkins"
snip
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.

For anyone who doesn't already know:

High speed DSL uses the second (home phone) wire for the computer downloads
and uploads, leaving the first (home phone) wire available for the actual
phone. This is why DSL customers can talk on the phone *and* be on the
internet - at the same time.

$25 for DSL hookup with Qwest (640K)
$19 for DSL ISP service with our old ISP company
------------------
$44 total ....per month for (24/7) 640K DSL

--
Montblack

"Montblack" wrote in message
.. .
High speed DSL uses the second (home phone) wire for the computer
downloads
and uploads, leaving the first (home phone) wire available for the actual
phone. This is why DSL customers can talk on the phone *and* be on the
internet - at the same time.

DSL runs on the same single phone line pair as voice. It uses frequencies
higher than those used for voice. It does not require a separate pair,
although sometimes it is set up this way for various reasons.

"Dr. Anthony J. Lomenzo" wrote:

While we're on the subject of 'juice' so to speak, in every power outage
up here in the north country [upstate NY] the phones are mercifully
still much welcomed operation but, here's the thing, while it's common
knowledge that 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?

The basic phone system runs on 48 volt DC. Most switches are located in
"Central Offices". These are manned stations. These contain battery banks,
which are constantly charged by commercial power supplies. Each office has
diesel generators to power chargers in the event of a power loss.

Developed areas which are not fairly close to small cities (or larger metro
areas) may connect to a "remote switching unit". These are located in unmanned
offices. These offices have backup power of some sort, usually diesel, but it
is expected that field personel will come out within a day or two to make sure
everything's OK. They cannot run indefinitely in backup mode.

Areas which are located far enough from the office will be served by digital
communication means. Multiplexed varieties of these systems are used in high
traffic areas, whether close to the C.O. or not. These digital centers and
optional multiplexers are located in unmanned stations. In the northeast, these
are usually underground in "controlled environment vaults". These CEVs have
battery backup power, but usually don't have generators. This requires that
field personel show up shortly with backup generators in an extended power
loss.

From your viewpoint, it doesn't matter if the CEV went down, the RSU went down,
or the CO went down. If any of the three happen, your phone is dead.

George Patterson
Brute force has an elegance all its own.