About Radius

RADIUS is the Remote Access Dial-In User Service, an Authorization, Authentication, and Accounting client-server protocol. RADIUS is the de facto industry standard for remote access AAA (Authentication, Authorization, Accounting) , as well as an IETF standard. In general, it's a network daemon (network process) which performs authentication, authorization and accounting actions when someone login on a Network Access Server with a dial-up client or logout from it.

Typically RADIUS server is used by Internet Service Providers (ISP) to performs AAA tasks.

But frequently, it's useful in a case when your need to provide any kind of controlled dial-up access in your organization. A technical specification of basic features which are supported by all radius servers you can find in RFC 2865/RFC 2138 and RFC2866/RFC 2139.

Courtesy of Ruslan R. Laishev, StarLet Group