This chapter discusses some widely used Diameter applications. Recall that application messages are exchanged between Diameter nodes only after capabilities have been discovered.
We will start with the application defined by the base specification, Base Accounting (Section 6.2), then look at another accounting application defined by the IETF called Credit‐Control (Section 6.3). Next, we will take a look at an authorization application to specify quality of service (Section 6.4). The section that covers the authentication application, Diameter Extensible Authentication Protocol (EAP), also has a
freeDiameter example (Section 6.5). The last and most complex application to be covered in this section is an authentication and authorization application used in mobile networks called the S6a Interface (Section 6.6).
Note that this chapter provides overviews of the applications' modes of operation, commands, and AVPs. The finer details for each application can be found in the application's RFC or technical specification.
We will cover some examples of these applications as they are extended by a standards development organization known as the 3rd Generation Partnership Project (3GPP) and deployed in mobile networks. The work of 3GPP is a good example of the adoption of Diameter and the development of Diameter applications. The area of mobile telecommunications provides fertile ground for Diameter applications due to the size of the networks, the heavy ...