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August 2007 | Volume 10 / Nuber 8
Feature Articles

A Note on Power Protection & Management

By Richard Grigonis

One thing that IP Communications equipment shares with older PSTN devices is that both run on the world's most remarkably unpredictable form of energy, electricity. Mother Nature sometimes hurls a bolt of lightning that can find its way via a power or modem line to a PC or server, frying some vital component in a millisecond. Blackouts or severe brownouts can disrupt everyday business too. Even if everything seems just fine, subtle, transient phenomena such as brief voltage surges provided by your friendly local power company slowly damages sensitive electronic equipment. Even tiny static discharges from your fingertips can shorten the life of PC semiconductor chips considerably.

Just about all of us probably own a simple power strip with a primitive surge protector consisting of wires and fuses set up to redirect high voltages before they reach (and destroy) your valuable equipment. Most work by suppressing incoming electrical surges before they reach your equipment by shunting the surge to a ground, most commonly via a metal oxide varister (MOV). Other suppressors add a filter or choke which, rather than unloading the entire thrust of a surge onto the ground wire at one time, releases a “captured” surge to the ground wire in small and controlled increments.

Given the number of horror stories related to power failure, most IT and IP Communications managers generally take more substantial steps toward protecting critical equipment such as phone systems and back office servers, which usually involves buying an Uninterruptible Power Supply (UPS) having built-in surge suppression and power conditioning.

Take for example the Liebert IP Telephony Availability System from Emerson Network Power ( which can deliver data center-level power protection to network edge equipment in remote access points, such as branch offices, retail stores, and other locations. It fits right in with stackable switches and routers, and it meets Cisco's AVVID (Architecture for Voice and Video Integrated Data) Partner Program test criteria for interoperability with Cisco CallManager Express 3.1 and Cisco Unity Express. Your local Liebert representative will help you tailor the system to work with your other equipment.

Liebert's OpenComms Web Card enables remote monitoring of the UPS, and allows you to remotely reboot attached Cisco equipment by cycling the UPS power off and on. For maintenance purposes, a 2U-high Liebert POD allows you to bypass the UPS and also provides power output distribution. If you're security conscious, you can place the system in a Liebert Foundation wall-mount or free standing enclosure that comes with a locking door and hinged back.

American Power Conversion, or APC as it's known ( is a huge company that has several families of UPS devices that work will with IP telephony equipment in general and Cisco VoIP equipment in particular.

For example, APC's Smart-UPS® & Smart-UPS® XL devices use a line-interactive topology and precise voltage regulation.

Then there's the Symmetra® line. At the low end is the APC Symmetra, an on-line double conversion unit that leverages paralleling capability to offer expansion and redundancy within the system by using multiple power modules. The Symmetra offers outputs from 2kVA to 6kVA (1.4kW to 4.2kW) plus redundancy. Next up is the Symmetra LX, also an on-line double conversion unit offering outputs from 4kVA to 16kVA (3.2kW to 12.8kW) plus redundancy. Farther up the scale is the Symmetra PX, another on-line double conversion device having a modular architecture as well as expansion and N+1 facilities, providing three-phase power protection from 10kVA to 80kVA (10kW to 80kW).

Control and management of power is another big consideration, particularly if the person in charge is nowhere near the equipment he or she is supervising. For these folks, Dataprobe ( offers the iBootBar, a new remote power distribution and management solution enabling web browser control of eight A/C power outlets for reboot and remote power control of multiple devices. A serial port or optional internal modem is also provided for out-of-band access when the network is unavailable. The iBootBar also supports Telnet, SNMP, SMTP and SSL security. Multiple iBootBars can be linked together to provide control of up to 128 outlets from a single IP address and web interface. The iBootBar can monitor networked equipment and will automatically reboot the equipment in the case of a system freeze. Dataprobe's AutoPing feature continuously monitors multiple IP addresses and takes programmed action when it detects non-responsive systems.

Even in the face of terrorist threats, power is taken for granted. Basic systems tend to be installed and kept out of sight and on the 'back burner', as it were. It's time to take a look at your power situation and perhaps upgrade to a new UPS system. IT

Richard Grigonis is Executive Editor of TMC's IP Communications Group.

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