Remote Access Authentication Protocol

Remote Access and Authentication procedures protect a network.

There are a number of authentication protocols for network access. However, the protocol that is specifically written to cater to Remote Access Authentication is the Remote Authentication Dial In User Service Protocol, or "RADIUS" for short.

Function

There are two servers guarding a network in the configuration of a remote access and authentication system, one is the Remote Access Server (RAS), the other is the Authentication Server. A user attempting to connect to the network contacts the RAS. This communicates with the authentication server on the user's behalf and communicates with the user on the Authentication Server's behalf. If the user proves his identity by passing the authentication challenge, the RAS then connects him through to the network.

Features

Access and Authentication are two parts of the RADIUS protocol's purpose. The other is "Accounting." That is, the RADIUS server keeps track of the users privileges and admits her only to the parts of the network and its services to which she has subscribed.

Application

RADIUS was used by all Internet Services Providers (ISP) for dial-up Internet access accounts. The advent of Broadband removed the step requiring the user to dial in and so made the RADIUS servers redundant. A new system of Internet access provision, Point to Point Protocol over Ethernet, collates many uses over one Broadband connection. This system returns to the older RADIUS system for access management.

References

• Untruth: An Analysis of the RADIUS Authentication Protocol
• Internet Engineering Task Force: Request for Comments 2865
• Carrick Solutions: What is the Difference Between PPPoE and PPPoA?
• Carrick Solutions: What is PPPoE?