Question: In a Policy and Charging Control (PCC) architecture, when a usage threshold for a monitoring key is reached, what action does the PCEF take regarding notification and reporting to the PCRF?
Option 1: The PCEF only notifies the PCRF without reporting accumulated usage, using a CCR command with CC-Request Type AVP set to "INITIAL_REQUEST".
Option 2: The PCEF measures but does not notify the PCRF until the IP-CAN session terminates, then reports all accumulated usage in a single CCR command.
Option 3: The PCEF notifies the PCRF and reports the accumulated usage for that monitoring key, including the "USAGE_REPORT" Event-Trigger in a CCR command with CC-Request Type AVP set to "UPDATE_REQUEST".
Option 4: The PCEF stops measuring usage for the service data flows and sends a termination request to the PCRF upon reaching the threshold.
Explanation: This is the correct action as per the described behavior in the context of Policy and Charging Control. When a usage threshold is reached, the PCEF (Policy and Charging Enforcement Function) is required to both notify the PCRF (Policy and Charging Rules Function) and provide an update on the accumulated usage for the specific monitoring key. This is done through a CCR (Credit-Control-Request) command with the specified settings to ensure seamless policy enforcement and billing accuracy in real-time.