Narus, a Mountain View company that helps telecom carriers manage their networks, has raised $30 million more in financing.

It includes $20 million in equity and a $10 million debt.

The equity component was led by American Capital Strategies, and included existing investors Mayfield Fund, Pacven Walden Ventures, J.P. Morgan Partners and NeoCarta Ventures.

Narus is one of those networking companies that has been around for a long time. Founded in 1997, it had already raised about $75 million. Most of its peers ended up crashing after the Internet Bubble burst in 2000, or selling for pennies on the dollar. Narus keepss pushing along.

It says it has experienced “strong growth” over the past three years, having developed ways to better manage the various layers of VoIP, data and video content being delivered over networks.

It says its customers include AT&T, Korea Telecom, KDDI, Telecom Egypt, Saudi Telecom, France Telecom and T-Mobile.