Quarry Technologies, a maker of equipment that carriers use to offer security services, this week announced it has raised $18 million in a fourth round of venture funding - the company's first in about three years.The Burlington, Mass., company has been around since 1998, when it was started by a group of routing and net management experts, and has received $95 million in funding to date. The latest round comes from new investor Westbury Partners and current backers 3i, Jerusalem Venture Partners, Arch Venture Partners, Sofinnova Ventures and Walden International.The vendor has focused from the start on selling routers to support IP services, though it has shifted toward enabling security services, such as IP VPN offerings, over the past few years. Last August, Quarry added an intrusion-detection system to its platform. The new funding will be used to market the company's routers and complementary management software, as well as further develop the products, such as by supporting new security functions. The investors say the company is worth backing because they see a growing willingness among corporate customers to buy security services in light of ever more dangerous and frequent network attacks.Quarry says three paying customers, including Korean carrier Dacom and upstart StraitShot Communications of Bellevue, Wash., are using its gear. Its products are also in trials at more than 10 carriers, according to a company spokesman. Quarry has been most successful selling overseas, but expects over the next year or so that its customer breakdown will be along the lines of 40% in the U.S., 40% in the Pacific Rim and the rest in Europe and other parts of the world.Quarry has refreshed its management team over the past year, hiring Ian Mashiter as president and CEO last July. (His previous company, edge switch maker Ennovate Networks, shut down in 2001 after raising $80 million-plus in funding.) Quarry has also hired vice presidents of sales\/service and engineering recently.Competitors include Cisco and Juniper, as well as CoSine Communications.