Cisco has now closed the second of three major multibillion-dollar acquisitions that it initiated in October. Today, the networking giant announced that it has wrapped up the acquisition of Starent Networks (NASDAQ: STAR) for $2.9 billion.

Cisco (NASDAQ: CSCO) originally announced its plans to buy Starent on Oct. 13. The smaller company's shareholders approved the deal on Dec. 11 and U.S. Department of Justice and Federal Trade Commission gave the transaction the go-ahead three days later.

Starent is a mobile Internet Protocol (IP) vendor that Cisco maintains will help to fill a gap in its wireless networking portfolio. One the define) market, a closely watched next-generation wireless broadband technology. A key Starent business is providing the gateways linking LTE to IP networks.

Starent Networks will now be folded into Cisco's new Mobile Internet Technology Group, which is part of the Cisco Service Provider Group (SPG). The former CEO of Starent, Ashraf Dahod, will become the general manager of the new mobile group within Cisco.

The new Cisco wireless division will compete against a number of vendors including Alcatel-Lucent (NYSE: ALU) as well as Ericsson, which now owns the former wireless assets of Nortel Networks.

The closure of the Starent deal marks the second major Cisco acquisition to be finalized this month.

Cisco successfully concluded its $183 million acquisition of SaaS security vendor ScanSafe at the beginning of December, just over a month since it first announced its plan to buy ScanSafe on Oct. 27.

The last remaining big deal from October that Cisco has yet to close is its acquisition of videoconferencing vendor Tandberg.

Cisco announced its intent to purchase Tandberg for $3 billion on Oct. 1.

However, a number of Tandberg shareholders balked at the deal as it did not value Tandberg on a price/earnings ratio as highly as Cisco's deal had valued Starent.

Since then, Cisco has upped the Tandberg bid to $3.4 billion and now controls more than 90 percent of the voting shares.

The U.S. Department of Justice is still in the process of approving the Tandberg deal.