PeerApp, an infrastructure company for Internet service providers that helps them deal with peer-to-peer traffic, has raised an $8 million second round of funding less than a year after taking its first.

The company's UltraBand caching system stores chunks of P2P files locally, so that repeated downloads of popular files don't overburden the network. Tangential to the needs of the ISPs, the product can also speed up the downloads for the end user.

Over 100 UltraBand systems have been deployed to date, according to the company's release, freeing up an average of 30 percent of an ISP's bandwidth for the circuits it's used on.

The funding round was led by existing investors Pilot House Ventures, Cedar Fund and Evergreen Venture Partners. PeerApp's first round, taken this January, was for $3 million. The company is based in Newton, Mass.