HP-UX AAA Server A.08.02 Administrator's Guide

Figure 1 Typical AAA Network Topology
Establishing a RADIUS Session
A RADIUS session tracks the life of a user session through a series of message exchanges. RADIUS
sessions are used to limit simultaneous access to a resource for users who share the same credential,
and to manage the allocation and release of IP addresses acquired on behalf of the user by the
AAA server. Figure 2 (page 23) illustrates the transaction between a RADIUS AAA server and a
client:
Figure 2 Client-Server RADIUS Transaction
When the user's device connects to the client, the client sends a RADIUS Access-Request to the
AAA server. When the server receives the request, it validates the sending client. If the client is
permitted to send requests to the server, the server then takes information from the Access-Request
and attempts to match the request to a user profile. If all conditions are met, the server sends an
Access-Accept packet to the client; otherwise, the server sends an Access-Reject packet. An
Establishing a RADIUS Session 23