USRobotics NETServer/8 - Manual (Page 262)

F-2 RADIUS
Security - A Centrally Managed User Table
The RADIUS security server is based on a model of distributed
security previously defined by the Internet Engineering Task
Force (IETF).
RADIUS’s client-server approach to security allows a network
administrator to maintain a single user table for all NETServers
on the network, rather than individual user tables for each box.
Each NETServer acts as a client of the RADIUS server.
NETServer acts as a client
TM
RADIUS Server
User Name
&
Password
User Table
Data
When a user dials into the NETServer, the NETServer first
checks its own User Table. If it can’t find the user, it then checks
with the RADIUS server (if it is configured to do so).
The NETServer encrypts the user name and password using an
encryption key shared by both the NETServer and the RADIUS
server, and passes the encrypted user name and password on to
the RADIUS server. The RADIUS server then checks the user
name and password against its users file, grants or denies
access, and passes this information back to the NETServer.
If access is denied, the NETServer disconnects. If access is
granted, the RADIUS server will forward the appropriate user
table information (such as what host or what protocol the user
needs).