Cisco has a goal of making the CTA open source within "a couple months," allowing the company to free up development resources for other areas of NAC, Gleichauf said. Cisco's decisionis 'more evidence that Cisco will cede control of the desktop to Microsoft Vista, following a deal in September to use the Microsoft's NAP (Network Access Protection Agent) as the client for both Cisco NAC and NAP.

"CTA will be something that's open source. That's just logically where it should end up," Gleichauf told InfoWorld. "We don't want to be in the CTA business, so we're going to just open it up."

In September, Cisco and Microsoft effort to integrate their network access control architectures. The called for computers running Windows Vista or Windows Server to include the NAP Agent component as part of the core operating system, and to use that agent for both NAP and NAC. The NAP added support Extensible Authentication Protocol over UDP and EAP-FAST support, developed by Cisco and distributed over Windows Update in addition to native EAP methods and an 802.1X supplicant to enable it to work for both NAC and NAP.

Computers running Windows XP with Service Pack 2, as well as non Windows systems, would need to run the Cisco Trust Agent for NAC and run the NAP Agent for NAP. Cisco also promised to continue developing CTA for non-Windows Vista and non-Windows Server 'Longhorn' platforms.

Since then, however, Microsoft and Cisco have extended both 802.1x and EAP support to Windows XP, reducing the need for the CTA, said Mark Ashida, General Manager of Enterprise Networking Servers at Microsoft.