How it Works

The SMF processes N11 messages with N2 message details to determine the accepted and failed QoS flow IDs. For failed QoS flow IDs, the SMF excludes the resources locally and communicates the following information to the external interfaces:

  • Sends the N4 Session Modification Request to UPF to delete the QERs, URRs, UL or DL PDRs, UL or DL FARs which are applicable to the QoS flow IDs.

  • Sends the Charging Data Update Request to CHF by including multi-unit usage details for the removed URRs. If SMF receives a usage report from UPF, SMF sends this report to CHF.

  • Sends the N1 N2 transfer message with N1 message details to UE as the PDU Session Modification Command.

  • Based on the received Policy Control Request Triggers and SM Policy Decision last Request Rule Data, SMF sends the Rule Reports SM Policy Control Update to PCF.