![background image](http://html.mh-extra.com/html/cisco/asr-5x00-home-enodeb/asr-5x00-home-enodeb_administration-manual_64831473.webp)
Rf Interface Support
How it Works ▀
Cisco ASR 5x00 Packet Data Network Gateway Administration Guide ▄
473
Figure 58.
Rf Call Flow for Session Based Charging
Table 41.
Rf Call Flow Description for Session Based Charging
Step
Description
1
The CTF receives a service request. The service request may be initiated either by the user or the other network element.
2
In order to start accounting session, the CTF sends a Accounting-Request (ACR) with Accounting-Record-Type AVP set to
START_RECORD to the CDF.
3
The session is initiated and the CDF opens a CDR for the current session.
4
The CDF returns Accounting-Answer (ACA) message with Accounting-Record-Type set to START_RECORD to the CTF
and possibly Acct-Interim-Interval AVP (AII) set to non-zero value indicating the desired intermediate charging interval.
5
When either AII elapses or charging condition changes are recognized at CTF, the CTF sends an Accounting-Request
(ACR) with Accounting-Record-Type AVP set to INTERIM_RECORD to the CDF.
6
The CDF updates the CDR in question.
7
The CDF returns Accounting-Answer (ACA) message with Accounting-Record-Type set to INTERIM_RECORD to the
CTF.
8
The service is terminated.
9
The CTF sends a Accounting-Request (ACR) with Accounting-Record-Type AVP set to STOP_RECORD to the CDF.
10
The CDF updates the CDR accordingly and closes the CDR.
11
The CDF returns Accounting-Answer (ACA) message with Accounting-Record-Type set to STOP_RECORD to the CTF.