More on Vonage service disruptions...

John R Levine johnl at
Fri Mar 4 18:50:24 UTC 2005

> This does bring up a hardware design question...I'm wondering how
> difficult of an engineering/marketing problem it would be to design
> VoIP adapters with built-in backup batteries. How does the power
> consumption profile of a VoIP adapter compare to, say, a cellphone?
> What would this add to the cost of the device, and how long could the
> battery last?

Funny you should ask.  POTS phones used to contain their own batteries,
but in the mid-1890s they switched to the current system that powers the
phone from the central office because maintaining the batteries was a
logistical nightmare.

I realize that things have advanced a little in the past century, but my
UPS still needs new batteries every year.  Since VoIP adapters have to
power POTS phones, their power needs are going to be those of POTS phones
rather than cell phones, and that means the battery has to provide enough
power to make the phone ring.

It's a fairly important part of the cableco system that their adapter with
the batteries is on the outside of the house so they can send guys around
to replace the batteries without the subscribers' help.  I don't see how
it'd ever be practical to get users of parasitic VoIP to maintain their
batteries since they'd only notice that the batteries had failed when the
power was out.

John Levine, johnl at, Primary Perpetrator of "The Internet for Dummies",
Information Superhighwayman wanna-be,, Mayor
"I dropped the toothpaste", said Tom, crestfallenly.

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