Final Unit Indication Support

The SMF supports Final Unit Indication (FUI) in the Charging Data Initial or Update Response from CHF as per 3GPP TS 32.291, section 6.1.6.2.1.12.

On receiving FUA, the SMF installs new FAR and associates its FAR-ID in the URR, in the FAR ID Quota Action IE. If a FAR with same parameters exists, the SMF uses its FAR-ID in the Create or Update URR. The UPF initiates appropriate actions set in FAR after quota exhaustion.

Currently, the SMF only supports Terminate and Redirect FU actions.

FUI in the Charging Data Initial or Update Response from CHF
Note
  • At any instance, CHF provides granted unit (Quota) to the SMF along with FUI.

  • When SMF receives the granted unit with FUI, the SMF creates FAR toward N4 and associates it to the corresponding URR which carries the Quota information.

  • After UPF receives the FAR associated with the URR, the corresponding FAR action is implemented when the quota exhausts.