Other NF instances are obtained through NRF
or created directly through configuration files.
Other NFs created by the config file should not be passed
through NRF discovery or anything like that.
Since self-created NF Instances do not have an ID,
they are implemented to exclude them from NRF Discovery.
The current load percentage of the NF Service Consumer is provided
in the payload body of the PATCH request when periodically
contacting the NRF (heart-beat).
AMF: ratio between currently connected ran_ue and maximum number of them
SMF: ratio between current PDU sessions and maximum available
PCF: ratio between current AM+SM policy associations and maximum available
or ratio between currently connected UEs and maximum number of them
(the load which is higher)
AUSF, UDM: ratio between currently connected UE and maximum number of them
BSF: ratio between current sessions and maximum available
NSSF: ratio between currently used NSIs and maximum number of them
NRF currently doesn't determine that the NF Profile has changed.
== Known limitation ==
Placing npcf-smpolicycontrol and pcf-policyauthorization
in different NFs is not supported. Both npcf-smpolicycontrol
and pcf-policyauthorization should be placed in the same NF.
1. UE registered and PDU established.
2. PCF does not receive Heartbeat.
- PCF De-registered state.
- Since PDU is established, SMF should not remove NF instance
3. PCF re-registered.
- HERE, WE NEED TO INCREASE NF REFERENCE COUNT.
Otherwise, NF instance will be removed if PCF is de-registered state
4. UE sends PDU release request.
5. Because SMF knows PCF NF instance, SMF can send PCF delete