The roadwarriors carol and dave set up a connection each to gateway moon using EAP-TTLS authentication only with the gateway presenting a server certificate and the clients doing EAP-MD5 password-based authentication. In a next step the EAP-TNC protocol is used within the EAP-TTLS tunnel to determine the state of carol's and dave's operating system via the TNCCS 2.0 client-server interface compliant with RFC 5793 PB-TNC. The OS IMC and OS IMV pair is using the IF-M 1.0 measurement protocol defined by RFC 5792 PA-TNC to exchange PA-TNC attributes.
carol sends information on her operating system consisting of the PA-TNC attributes Product Information, String Version and Forwarding Enabled up-front, whereas dave must be prompted by the IMV to do so via an Attribute Request PA-TNC attribute. carol is then prompted to send a list of installed packages using the Installed Packages PA-TNC attribute whereas dave's "Windows 1.2.3" operating system is not supported.
carol passes the health test and dave fails. Based on these assessments which are communicated to the IMCs using the Assessment Result PA-TNC attribute, the clients are connected by gateway moon to the "rw-allow" and "rw-isolate" subnets, respectively.