The encyclopedia publisher's online service (www.eb.com) is growing fast as well, as is its increasingly popular Internet portal, www.britannica.com. The latter provides a search engine with a twist: Each site in this portal's directory has been reviewed and qualified by one of the editors at the publishing company. Encyclopaedia Britannica says it wants www.britannica.com to become for surfers what the leather-bound volumes were to pencil-pushing researchers.

"We are becoming primarily an Internet company," says Doug Shuck, CIO for Encyclopaedia Britannica, based in Chicago. "As more consumers demand Internet access for their research, we will focus mainly on the Internet."

As part of its Internet strategy, Encyclopaedia Britannica has built load-balancing technology into its five Web server sites around the globe. Each site--London, Herndon, Va., Chicago, Sunnyvale, Calif., and Melbourne, Australia--runs an F5 Big/ip load-balancing appliance. If one of the Web or transaction servers gets overloaded or crashes, the appliance redirects traffic to a healthy, available server.

Encyclopaedia Britannica has redundant connections to each site, too. Its Chicago site, for instance, features multiple T1 and DS-3 links to the Internet, as well as some wireless links for backup. "Everything is totally redundant with automatic failover," Shuck says. The publisher also runs F5 3DNS appliances for automatic failover on the WAN side. If the response time of one of its sites slows or fails, the 3DNS sends traffic to one of the other four sites on the WAN, typically the one that is closest geographically to the user. "It automatically determines where the user will get the best possible service," Shuck says.

Still, like many businesses today, Encyclopaedia Britannica doesn't conduct so-called "static" load-balancing among its WAN sites. "We're not sending 10 percent of traffic to Chicago, and 15 percent to Australia," for instance, he says. The load-balancing appliances monitor server allocation and availability. "If one is close to capacity or experiencing difficulties, we can manage it without inconveniencing our users," he says.

When bandwidth becomes more critical in the future, Encyclopaedia Britannica plans to deploy QoS (Quality of Service) features to fine-tune both its online resource service and its portal; some load-balancing products already are starting to ship with QoS protocols. "We will prioritize search and transaction [traffic] where different data requires different levels of performance," says Shuck, such as video, audio, e-commerce and other high-bandwidth traffic.

"Our job now is to continue Encyclopaedia Britannica's legacy of breadth and depth of information and quality of delivery onto the Internet and beyond," he adds.