Diameter

Read this article about the history of Diameter and why it was developed. What preceded Diameter as an authentication protocol? While you do not need to understand how Diameter authenticates, you should have a general idea of its authentication process.

1.Introduction

DIAMETER is the newest AAA protocol developed in 2001 from the older AAA protocol RADIUS (Remote Access Dial-In User Service) by the Internet Engineering Task Force (IETF) as an Authentication, Authorization, and Accounting (AAA) framework intended for applications such as remote network access and IP mobility. The DIAMETER protocol was developed to resolve the issues that RADIUS left open. In new application areas like Wireless Local Access Network (WLAN) and Voice over IP (VoIP), DIAMETER is better suited and gives better support for roaming users. DIAMETER is defined as a base protocol used in conjunction with a set of applications. The Diameter Base Protocol [RFC 6733] contains the basic functionality like reliable transport, message delivery and error handling. The Diameter applications are extensions of the basic functionalities that are tailored for a particular usage in a particular environment.

AAA Framework includes: 

  •  Authentication is the verification of the identity of the entity. 
  •  Authorization is the determination whether the requesting entity is allowed access to a particular resource. 
  •  Accounting is the collecting of information about resource usage for the purpose of capacity planning, auditing, billing or cost allocation.