Charging Session
The SMF supports converged session-based charging (SCUR) as specified in 3GPP TS 32.290, section 5.3.2.3.
The SMF establishes charging session with the CHF with the Charging Data Request and Response (Initial) exchange. During the life of the PDU session, usage is reported with Charging Data Request/Response (Update) exchange. After the session is released, Charging Data Request/Response (Termination) messages are exchanged.