Microsoft has announced that its Network Access Protection (NAP) network access control (NAC) system will now interoperate with the

Trusted Computing Group's (TCG) architecture, Trusted Network Connect (TNC).

Microsoft's general manager of the core networking and collaboration group in Windows networking, Henry Sanders, said that, "NAP’s Statement of Health protocol, included in Windows Vista, is now the standard client-server communication protocol within TNC. This means Microsoft’s NAP is now interoperable with the two other primary NAC architecture solutions, TNC and Cisco’s NAC."

One of the potential issues holding back NAC enterprise uptake was interoperability concerns between the three main architectures - Cisco's Network Admission Control, Microsoft's NAP and the TCG's TNC.

In its recent market size and forecast report, figures from consulting firm Infonetics Research showed that the NAC appliance market quadrupled between 2005 and 2006, reaching $83 million. The EMEA region accounted for a quarter of the market, which is set to double in 2007.