The Accounting Interworking Function that will activate the online-charging session, and provide relevant input information for the OCS decision. i.e. subscriber identifier and charging keys obtained in step A.1.
The Accounting Interworking Function may contact the OCS to request credit for new charging keys and/or to issue final report and return remaining credit for charging keys no longer active, i.e. when the accounting session is terminated.
The OCS may instruct the Accounting Interworking Function on the further handling of the session (terminate, continue, etc), provide credit information (possibly with re-authorisation trigger), and/or acknowledge the credit report.
This procedure is performed when BNG send a stop accounting message to the Accounting Interworking Function, for example the IP-CAN session termination procedure is initiated by PCRF or when Subscriber IP session terminated (for example when the 3GPP UE disassociates from the fixed broadband network, the RG is switched off, etc.).
The BNG determines that the Subscriber IP session is terminated (e.g. the device has left the fixed broadband network) and consequently a PCEF-Initiated IP-CAN session termination is initiated or it shall be terminated, when PCRF-Initiated IP-CAN session termination procedure is performed.