Launched close to the one-year anniversary of the crippling denial of service (DoS) attacks that struck some of the nation's largest e- commerce sites, a new security firm says it can reduce drastically the impact of such attacks.

Waltham, Mass.-based Arbor Networks intends to start marketing its DoS- prevention services to ISPs, major Web sites and other entities susceptible to the simple, but hugely disruptive attacks, Arbor Chief Strategist Ted Julian said Friday. Since DoS attacks disable Web sites and routers by flooding the servers with bogus information requests, technicians must wade through thousands of lines of code to find the source of the attack, Julian said. As a result, successful DoS attacks, like the one launched against Microsoft Corp.'s Web site routers just last month, can bring sites down for hours and even days, depending on how fast the attacks are detected. But Arbor's technology - which both Julian and Arbor Chief Technology Officer Rob Malan claim is the first of its kind - automatically scans Web traffic and alerts customers to any suspicious activity. The technology then traces the source of the activity and alerts service providers so that they can shut off the source of the attacks, Malan said. Since the software tracks attacks back to their source, it can cut down enormously the amount of time needed to fix the problem, Malan contends, adding that if Microsoft had had the Arbor technology in place two weeks ago, it could have stopped the attack in minutes rather than hours. Arbor founders developed the DoS-prevention software at the University of Michigan and planned their launch to coincide with the anniversary of last year's brutal DoS attacks that struck Amazon, eBay, CNN.com and many others among the Internet's largest sites. Arbor is backed by Battery Ventures and Cisco Systems, which have invested a combined $11 million.