Network Appliance Corp has won internet service provider PSINet Inc as a customer for its dedicated cache appliances, the company said Thursday. PSINet is using the NetApp appliances to speed up a specific heavy traffic web site it hosts for NASA – the Human Spaceflight Web site – and put the equipment in place in time for the build-up in traffic caused by public interest in the John Glen mission last October.

The NetCache equipment has been deployed in major PSINet data centers in the US as a reverse proxy server or web accelerator, in order to speed up the NASA site and reduce costs associated with bandwidth. West coast visitors to the site, for instance can access cached materia held in California rather than going straight to the Virginia site. NetApp’s technology enables a single site or multiple sites to be targeted with extra cache.

NetApp runs its NetCache division as a separate virtual business unit alongside the mainstream network-attached storage business, although the NetCache units use the same base hardware. Last quarter, the company generated $5.8m in revenues from its cacheing business, out of a total of $75.6m. Most were to internet service providers, although the company says corporate sales are now also beginning to move.

The NetCache division was formed from the acquisition in 1997 of Internet Middleware Corp, the company run by cacheing pioneer Peter Danzig. Danzig worked on the Squid and later Harvest freeware cacheing projects which still compete with NetApp’s commercial products today. NetApp used Harvest as the basis for its own product, but has since replaced around 95% of the code. Otherwise, the main competition comes from Inktomi Corp, although Compaq Computer Corp has recently announced plans to enter the market in conjunction with Novell Inc.

Other customers of NetCache include international telecommunications companies such as Hongkong Telecom and Singapore Telecom.