Feature Description
PCF is equipped to retrieve the event triggers from the SMF by sending the N7 Notify Request. Certain features such as Rx or N5 bearer authorization, QoS derivation, and rule evaluation depends on specific event triggers such as RAT-Type and AccessType for taking the appropriate action. For instance, the RAT-Type event trigger lets you determine the Radio Access Technology (RAT) that is serving the User Equipment.
Typically, PCF does not subscribe to all the event triggers during the session initiation using N7 Create. If the features are dependent on specific event triggers and PCF did not subscribe to them, then PCF does not fetch the values associated with those events. With the dummy N7 Notify Request, you can send an intermediate request to fetch the event triggers corresponding to the configured Media-Type which is specified in the Rx AAR or N5 Create message from the IMS.