What is an AAA server? In Diameter Protocol.
AAA is an abbreviation that stands for Authentication, Authorization, and Accountability. In the telecom network, it is the most fundamental thing to determine whether or not a mobile subscriber is permitted to use a service, such as voice, internet, or other services.
In the diameter protocol, the AAA server is pretty common. A client can make contact with the AAA server in order to gain access to a resource.
When a mobile user wants to connect to the internet, the sim card must first obtain access from the AAA server.
What is Authentication?
It is the process by which a user or client sends an authentication request along with his or her credentials. A simple user name and password can serve as the authentication credentials. If the user is permitted, the AAA server responds with a successful response, otherwise, responds with a failure code.
What is Authorization?
To allow granting for a service. The service can be a call, SMS, or data.
What is Accounting means?
AAA server keeps the record for all services-specific units. E.g how many calls, how, much data a device has been consuming over time.
How AAA works in telecom networks?
Authentication, The GGS/PGW sends an Initial CCR to the AAA server, the credentials are IMSI (user name ) and password (optional).
Authorization, In initial CCR and update CCR during a data session, PGW/GGSN requests for the bytes to a UE. AAA server grants/authorizes the same number, more or less.
Accounting, The AAA server keeps all data records against the IMSI. The records may use for billing, future resource planning, etc.