12Figure 6 Basic message exchange process for a Telnet userHWTACACS operates in the following manner:1. A Telnet user sends an access request to the HWTACACS client.2. Upon receiving the request, the HWTACACS client sends a start-authentication packet to theHWTACACS server.3. The HWTACACS server sends back an authentication response to request the username.4. Upon receiving the response, the HWTACACS client asks the user for the username.5. The user enters the username.6. After receiving the username from the user, the HWTACACS client sends the server acontinue-authentication packet that carries the username.7. The HWTACACS server sends back an authentication response, requesting the login password.8. Upon receipt of the response, the HWTACACS client asks the user for the login password.Host HWTACACS client HWTACACS server1) The user logs in2) Start-authentication packet3) Authentication response requesting the username4) Request for username5) The user inputs the username6) Authentication continuance packet with theusername7) Authentication response requesting the loginpassword8) Request for password9) The user inputs the password11) Authentication response indicating successfulauthentication12) User authorization request packet13) Authorization response indicating successfulauthorization14) The user logs in successfully15) Start-accounting request16) Accounting response indicating the start ofaccounting17) The user logs off18) Stop-accounting request19) Stop-accounting response10) Authentication continuance packet with thelogin password
