Question: In a Policy and Charging Control (PCC) architecture, what information is passed from the Policy and Charging Rules Function (PCRF) to the Application Function (AF) for charging correlation between service data flow level and application level (e.g., IMS)?
Option 1: Applicable charging identifiers and IP-CAN type identifiers
Option 2: Only Applicable charging identifiers
Option 3: Subscription data and ADC Rule information
Option 4: PCC rule information and TDF parameters
Explanation: For effective charging correlation between the service data flow level and application level (such as IMS), and to support online charging at the application level, it is crucial to share specific identifiers. The PCRF passing applicable charging identifiers (to correlate charges) and IP-CAN type identifiers (to identify the IP Connectivity Access Network type, which can influence charging policies) to the AF ensures seamless integration of charging mechanisms across different levels of service delivery. This aligns with the principles of PCC architecture for granular and flexible charging control.