Switching to VoIP

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Disaster Survivability

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Unlike analog phones on the PSTN, VoIP systems don’t get their

power from the PSTN. VoIP systems will fail during power outages

unless they have adequate backup power.

Multiphase power

Most small offices and residences receive their AC power in the form of a single 120/

240-volt connection. This connection feeds a circuit-breaker block that distributes

individually limited power circuits throughout the premises. When the power fails at

the breaker block, the power fails for the entire premises.

But when power is delivered in multiphase, it can create redundancy. Multi-phase

power means that the same connection to the electric company can deliver two or

three AC supplies to the subscriber’s premises. The supplies are connected to sec-

tions of the breaker block or to different breaker blocks. So, when a single phase

fails, the other phases are still intact, and equipment on the failed phase can be

moved to them. This won’t eliminate all failures, but it can protect you against cer-

tain kinds of failures that occur within the electric company’s facilities.

Uninterruptible power supplies

In order to survive a power failure, all of your network equipment must remain run-

ning—switches in phone closets, servers at the data center, and IP phones them-

selves. This ...