Final Unit Indication Support

The SMF supports Final Unit Indication (FUI) in the Charging Data Initial/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 it's FAR-ID in the URR, in the FAR ID Quota Action IE. If a FAR with same parameters exists, the SMF uses it's FAR-ID in the Create/Update URR. The UPF initiates appropriate actions set in FAR after quota exhaustion.

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

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.

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