Network security firm raises $22 million

Network security software maker Arbor Networks said Monday that it closed $22 million in a second round of funding. Investors included Thomas Weisel Venture Partners, Cisco Systems, Battery Ventures, Comcast and IT services firm Science Applications International. Arbor Networks has now raised a total of $33 million.

The company, based in Lexington, Mass., also said it has hired Thomas Arthur as its new chief executive. Arthur is the former president of ActivCard, a French developer of digital identity and certification technology. Arbor's software is designed to help Internet service providers, government agencies and other businesses protect their computer networks from denial-of-service attacks and other threats.