SmartPipes closed its fourth funding round at $51 million, the company announced Monday, with contributions from new investors such as Microsoft, Juniper Networks, Intel Capital and Invesco Private Capital. Previous investor Kleiner Perkins Caufield & Byers also participated in the round, which brings the company's total financing to $116 million since its founding in 1999. Some of the Redwood City, Calif.-based company's past backers include Dell Computer, WorldCom and XO Communications
SmartPipes makes software that helps telecom carriers run virtual private networks and security services as well as manage telecommunications gear at their customers' sites. The company will use the funds to develop new features for its software.