Ehternet cableVSS Monitoring, a provider of network taps to monitor network traffic, raised $20 million on Tuesday in the company’s first round of venture-capital funding from Battery Ventures — five years after the company launched its first product.

Prior to Battery Ventures’ funding, VSS Monitoring had developed its product and sold it without outside investment. The $20 million funding from Battery Ventures is pegged to help promote research and development and expansion. Battery Ventures partner Neeraj Agrawal and principal Alex Benik will join VSS Monitoring’s board as part of the deal.

The Burlingame, Calif.-based company provides software and hardware to monitor large networks, improving security and preventing traffic bottlenecks that would otherwise throttle network performance. It was founded in October 2003 by current CEO Terence Breslin and launched its first product in January 2005.

As network speed and traffic increases over time, there’s growing interest in companies that produce hardware and software to monitor traffic — especially for security purposes. Gigamon, another provider of network monitoring hardware and software and a major competitor to VSS monitoring, raised $22.8 million in February.

Battery Ventures has funded several breakout companies like @stake, Airespace, Akamai Technologies and Omniture. Its current investment portfolio includes companies like Anobit, Arbor Networks and GreenBytes. Battery manages nearly $4 billion in committed capital in addition to its current fund of $750 million.