In order to view NAC session data, select Monitoring > Sessions.
The Monitoring Sessions window opens.
Click an entry in the Username column to display the session details. The Administration > Administer Sessions > Detail window also contains information about NAC-enabled sessions. This illustration shows the Network Admission Control section of the session details table.
For further information click this link.
http://www.cisco.com/en/US/products/hw/vpndevc/ps2284/products_configuration_example09186a008049863d.shtml#s6