Cisco Systems agrees to purchase IronPort, a provider of messaging and Web security applications. Over the last several years Cisco Systems has expanded its security offerings with firewalls and NAC (network admission control) authentication tools. The IronPort software will complement the Cisco threat mitigation, secure communications, policy control and infrastructure management technologies. The IronPort products are built on two proprietary e-mail security technologies: SenderBase and AsyncOS. SenderBase is an e-mail traffic monitoring service that identifies potential sources of bulk spam, and detects suspicious behavior and virus outbreaks.