The IMS AAA Server is a multi-protocol, AAA server that enables 2G/3G GSM/UMTS mobile operators to support 3GPP WLAN services including UMA (Unlicensed Mobile Access), Femtocell and IMS (Release 6) based I-WLAN. The IMS AAA Server performs SIM-based (Subscriber Identity Module) authentication, subscription authorization, and accounting (AAA) in 3GPP WLAN Interworking environments where the primary subscriber database is a Home Subscriber Server (HSS).
This chapter covers the following topics:
- IMS Background
- 3GPP WLAN Interworking
- Overview of IMS AAA Server AAA Functions
- Basic IMS AAA Server Configuration Concepts
- Diameter Configuration Overview
- RADIUS Configuration Overview
- Local IMS Policy
- Request Routing
- RADIUS/Diameter Translation
- IMS AAA Server Administrator
The IMS AAA Server supports both the RADIUS and Diameter protocols which are both industry standard methods for providing authentication, authorization, and accounting (AAA) services:
- Authentication is the process of verifying a subscriber's identity and associating additional information (attributes) to the subscriber's login session.
- Authorization is the process of determining whether the subscriber is allowed on the network and controlling network access values based on a defined security policy.
- Accounting is the process of generating log files that record session statistics used for billing, system diagnosis, and usage planning.
The IMS AAA Server performs the AAA functions of the 3GPP AAA Server/Proxy referenced in 3GPP TS 23.234: 3GPP System to Wireless Local Area Network (WLAN) Interworking; System Description in networks that support IMS Release 6.