Basics of Diameter Protocol

Basics of Diameter Protocol:

Diameter is a Authentication Authorization and Accounting (AAA) protocol. It works on the Application Layer if we consider OSI Layered model.

Example of AAA protocol:-

Any User trying to access a Network (Ex: Internet Service Provider) has to undergo “AAA” procedure that is being implemented by that Network. 1. Authentication: The network will validate that its an Authenticate User. 2. Authorization: The network will authorize the services requested by the User. 3. Accounting: The network will keep a track of usage made by the User.

While performing the above three steps, the Network may reject the User from using the service at any point and that is how security is maintained and hence the importance of AAA protocol.

So, Diameter basically is a message based protocol, where AAA procedure may occur and the AAA nodes exchange messages and receive Positive/Negative acknowledgment for each message exchanged between nodes.