All true telco equipment is powered by batteries. Commerical power or
generators just recharge the batteries. No switch over when commerical
power is lost. Except when the generators(where equiped) switch over to
recharge the batteries.
Comcast and telcos do not put batteries in all remote powered
terminals. I have an Enterprise grade Ethernet over coax connection.
The headend it's distributed from doesn't have batteries. If it loses
power, doesn't matter if I have power or a generator or ups to take
over. This Internet connection goes down.
For telcos(when I worked there), they usually had batteries that would
last 4 to 8 hrs at remote terminals with powered equipment. And a
connection for a splice crew to come out and connect their generator to
it for power in case of an extended outage. Back then that was also how
most cell phone towers were outfited.
I also have some knowledge of the commerical power grid in my local
area. It's not unheard of for the Comcast headend to lose power but my
office doesn't.
Lyle Giese
LCR Computer Services, Inc.
On 10/14/19 17:38, Michael Thomas wrote:
On 10/14/19 3:06 PM, Sean Donelan wrote:
That is not why people are surprised. When the house doesn't have
power, and doesn't have home generator or UPS, (most) people are less
surprised their DSL or Cable modem and VOIP doesn't work anymore.
The reasons I saw people angry on twitter was no Comcast service even
when they had power at the house (utility, generator, UPS). Their
Comcast service died quickly, even when the home had power but the
Comcast outside plant didn't seem to have any backup power.
DSL modems also need power at the home, but the telco providers seem
to have more backup power in the outside plant or central offices.
That meant DSL worked as long as the house had power (or a home
generator or UPS).
So it turns out that our local telco/isp does keep dsl running via the
same mechanism as they keep pots power backed up (i'm guessing it's a
diesel generator at the co, but am not sure). It seems that a lot of
the pedestals terminating the local loop these days do the conversion
to IP right there with sip/h.248/mgcp/rtp. I'm not sure how they get
power to the pedestal, but these were all a home run to the co at one
time so it probably wasn't hard to power them from the co. For all i
know, that's how they're all powered all the time, with a transfer
switch at the co, rather than tapping the local grid next to the
pedestal.
Of course this is a lot of conjecture on my part... be glad to be
clued in by folks in know.
Mike