RADIUS server is responsible for getting user connection requests, authenticating the user and then returning all configuration information necessary for the client to deliver service to the user.
A RADIUD server can act as a proxy client to other RADIUS servers.
Network Security:
Transactions between client and server are authenticated through the use of a shared key and this key is never sent over the network.
Password is encrypted before sending it over network.
Flexible Authentication Mechanisms:
RADIUS supports following protocols for authentication purpose:
Point-to-Point Protocal - PPP
Password authentication protocol - PAP
Challenge-handshake authentication protocol - CHAP
Simple UNIX Login
Extensible Protocol:
RADIUS is extensible; most vendors of RADIUS hardware and software implement their own dialects.