CDR Process Overview
The CDR capability manages all CDR-based subscriber accounting for the purposes of billing. CDRs are forwarded to a charging gateway through an FTP server, or other transport method to a billing application.
Figure 13 shows the call detail record (CDR) accounting process.

The following steps take place after account provisioning and authentication:
After it receives a RADIUS Access-Accept message, the Access Controller grants the subscriber access to the network, and sends a RADIUS Accounting-Start message to Steel-Belted Radius Carrier.
Steel-Belted Radius Carrier passes the Accounting-Start message to the Call Detail Record (CDR) accounting engine (cdracct), and determines whether accounting requests have been previously received for the account.
Steel-Belted Radius Carrier records fixed-fee, session, or partial CDRs to the accounting file system.
The service provider periodically exports CDR billing information to a billing application.