A.22 Monitoring of N4 session management
28.5523GPP5G performance measurementsManagement and orchestrationRelease 18TS
UPF handles the user plane path of PDU Sessions. UPF selection is performed by SMF, and deployments where a UPF is controlled either by a single SMF or multiple SMFs (for different PDU Sessions) are supported.
The SMF uses N4 session management procedures to control the traffic detection, traffic reporting, QoS enforcement and traffic routing of the UPF.
The N4 session management procedures include N4 Session Establishment procedure, N4 session Modification procedure and N4 session release procedure.
If PDF fails to handle the user plane path for a PDU session, the user service will be impacted. So the performance about N4 session management needs to be monitored.