he electricity that powers computer systems can sometimes be the source of security problems, rendering important computer data unavailable. Power outages are one threat; variations in the quality of the current are another problem. Blackouts, sags (short-term voltage decreases, also known as brownouts), spikes (instantaneous, dramatic increases in voltage), surges (short-term voltage increases) and line noise can degrade or destroy hardware and wipe out unsaved (or in extreme cases all) data. Sources of these problems include lightning, downed power lines, peak-period electricity demands, and the power needs of other high-powered electrical motors on the line.
Several types of products are available to overcome these threats. Surge suppressors are a ubiquitous piece of equipment used between computers and outlets to guard against surges and spikes. Power conditioners also protect against sags by keeping the voltage reaching the computers within an acceptable range. Uninterruptable power supplies (UPSs) are installed on many government computer systems as complete protection against power disruptions. The units supply about 10 to 15 minutes of battery power once the regular supply is lost, which is enough time to switch to a generator, if one is available, or to save data and safely shut down the system.
UPS units are "ubiquitous" at the General Services Administration, says the GSA's Heffernan. "They're not just for mission-critical [systems], but for all local area network servers and up," he says.
UPS units are becoming smaller, cheaper and smarter. The newest products on the market feature multiple batteries to minimize the odds of battery failure.
In a network environment, a complete UPS solution includes power management software to allow systems administrators to control and monitor power across a network from a central workstation. The software displays power system status for points along the network. If a systems administrator is absent during a power emergency, some software can page them.
American Power Conversion, Exide Electronics and Best Power sell UPS units, power conditioners and surge suppressors for a range of computer systems. Prices for UPS units start at about $100 for workstation-level protection and go above $10,000 for UPS units serving high-end data centers with many servers.