Oracle, the second-largest maker of business applications, agreed to acquire Acme Packet Inc. for some $2.1 billion, gaining technology that helps networks securely deliver information.

The software giant will be able to bolster the communications package it offers to customers with the acquisition, it said Monday. Acme makes phone and data network equipment that’s used by more than 1,900 service providers and enterprises around the world.

Oracle (Nasdaq: ORCL) will pay $29.25 a share in cash, according to a statement today. That marks a 22 percent premium over Acme’s stock price on Feb. 1, the most recent trading day.

For Oracle, the deal extends an acquisition spree that began in 2005 and pushes the company deeper into networking technology – a market that’s benefiting from the boom in mobile devices.

“The communications industry is undergoing a dramatic shift as users become more connected and dependent on mobile applications and devices,” Bhaskar Gorti, senior vice president and general manager of Oracle Communications, said in the statement. “Service providers and enterprises need a comprehensive communications solution that will enable them to more effectively engage with their customers.”

Acme shares had fallen 1 percent to $23.93 on Feb. 1, while Oracle’s stock gained 2 percent to $36.21.

Shares of Acme Packet Inc. soared 23 percent, or $5.57, to $29.50 in premarket trading. Oracle Corp. shares lost 44 cents to $35.77.

Acme’s board unanimously approved the acquisition, which is expected to close in the first half of 2013. The deal remains subject to Acme shareholder and regulatory approval.