Cache in hand: Appliance-like devices allow providers to move data closer to users

Internet service providers face the same issues carriers face when it comes to their network resources. Building new infrastructure at the rate at which demand is increasing isn't financially feasible, so instead of building new "pipes," service providers have to find smarter ways to use the pipes they already have.

For ISPs, one answer may lie in caching, a technology that's already in use in the desktop computers and data storage systems they use daily. Web caching-the storage of frequently-used data on high-speed storage devices deployed at points of presence (POPs) in the network-can allow end users to get their most important data more quickly while reducing the amount of traffic on the network.

Cache memory stores recently used data and maintains it in a quickly accessible form for a duration based on algorithms that may vary among caching devices. Rather than accessing an internal or external Web site, an end user trying to call up a recently accessed site will receive the stored copy of that site instead of waiting for a connection over the Internet.

"Caching is already ubiquitous, only we don't see it," said Robert Gray, research manager for storage subsystems at International Data Corp. "It's invisible, for the most part, and it already is used in the ISP world in storage systems. But as it becomes a technology that's used more as part of the network, it could give service providers the ability to outsource new services and generate new revenue very easily."

While software solutions for caching exist, they usually are parts of other systems and require additional effort to manage and administer. Earlier this month, Network Appliance announced a hardware approach. NetCache provides caching functionality but does so as an independent network element.

"This allows the units to be at home even in low-end POPs in 'lights out' situations," said Rich Boberg, senior director of Internet marketing at the Santa Clara, Calif.-based Network Appliance.

"This is an integrated, dedicated caching appliance and as such is extremely simple to administer," he said.

The NetCache is essentially a "thin server," with just the intelligence to perform the caching job.

In practice, the use of such devices helps both service provider and end user, said Boberg. "We've found that 30% to 50% of the objects requested are in the cache memory," he said. "The customer gets those objects in the low milliseconds, plus that's 30% to 50% of the traffic that would have gone over the Internet that has been satisfied close to home."

While the market for Web caching devices is just emerging, the advent of push technology could help speed the deployment of such applications, according to one analyst.

"When you inject push technology into the network, things get interesting," said Brendan Hannigan, a senior analyst at Forrester Research, Boston. "Instead of having to push to every user's PC, you can push data to their local cache. Then you go from a model where the network is used to bring users to content to a situation where the network brings content to the users."