AAA and Network Security for Mobile Access: Radius, Diameter, EAP, PKI and IP Mobility

7.3. Details of Diameter Applications

As mentioned before, most of the Diameter applications are defined in separate specification documents, except the Diameter accounting application that is described within the Diameter base specification [DIMETER3588]. We provided a high level overview of several Diameter applications earlier. In this section, we will go through several of these applications in more detail.

7.3.1. Accounting Message Exchange Example

In contrast to RADIUS, accounting methods are specified within the Diameter base protocol specification. Even though the messaging for accounting in the Diameter base specification is rather brief, the IETF AAA working group has spent some energy on providing more guidance on accounting management and its attributes by producing two other RFC specifications ([ACCMGM2975] and [ACCATT2924]). The highlights of accounting management ([ACCMGM2975]) documents were given in the first chapter of this book. The reader is referred to [ACCMGM2975] for more information on accounting attributes for a variety of AAA protocols.

Figure 7.3. An example of Diameter accounting application exchange

Figure 7.3 shows a sample message exchange for Diameter accounting application. The names of the messages are self-explanatory. The capability exchange messaging is included for completeness to make sure that both nodes support the accounting application. ...