3Com MSR 50 Series Configuration Manual page 1754

1754 C 93: AAA/RADIUS/HWTACACS C
HAPTER ONFIGURATION
information in the authentication response message. For interaction among the
host, RADIUS client, and RADIUS server, see
Figure 512 Basic message exchange process of RADIUS
Host
1) Username and password
9) Notification of access termination
The following is how RADIUS operates:
1 The user enters the username and password.
2 Having received the username and password, the RADIUS client sends an
authentication request (Access-Request) to the RADIUS server.
3 The RADIUS server compares the received user information with that in the Users
database. If the authentication succeeds, it sends back an Access-Accept message
containing the information of user's right. If the authentication fails, it returns an
Access-Reject message.
4 The RADIUS client accepts or denies the user according to the returned
authentication result. If it accepts the user, it sends an accounting start request
(Accounting-Request) to the RADIUS server, with the value of Status-Type being
"start".
5 The RADIUS server returns a start-accounting response (Accounting-Response).
6 The subscriber accesses the network resources.
7 The RADIUS client sends a stop-accounting request (Accounting-Request) to the
RADIUS server, with the value of Status-Type being "stop".
8 The RADIUS server returns a stop-accounting response (Accounting-Response).
9 The subscriber stops network resource accessing.
RADIUS packet structure
RADIUS uses UDP packets to transmit messages. It ensures the smooth message
exchange between the RADIUS server and the client through a series of
Figure
RADIUS client
6) The subscriber accesses the resources
512.
RADIUS server
2) Access-Request
3) Access-Accept
4) Accounting-Request (start)
5) Accounting-Response
7) Accounting-Request (stop)
8) Accounting-Response