Feature Description
The CHF server interacts with PCF to report the user quota exhaustion. Then, the PCF initiates a policy update request towards SMF to modify the authorized default Quality of Service (QoS) of a session rule. The QoS can be QoS Class Identifier (QCI) or 5G QoS Indicator (5QI), session Aggregate Maximum Bit Rate (AMBR), or both QCI/5QI and session AMBR.
Whenever the quota of user exhausts, this QoS modification results in downgrading:
-
the DSCP marking of the data packets for the session
-
the AMBR of the session
When you replenish the quota, the PCF reverts to the previous authorized QoS for the default bearer.
Be aware of the following changes whenever the QCI/5QI changes for the default flow or bearer.
-
The QCI/5QI information is updated in the Event Data Record (EDR) generated for that session. Then, the SMF sends the updated bearer level information over Packet Forwarding Control Protocol (PFCP) message to support the EDR functionality.
-
DSCP marking for the data packets is updated for all Packet Detection Rules (PDRs) pertaining to the default bearer or flow.
-
Any QCI information sent in LI packets are updated.
-
Rulebase change and Ruledef activation or deactivation work as expected along with 5QI change and session AMBR change.
-
Any modified QoS is sent in Charging Data Request (Update) message to the CHF. Also, change in QCI/5QI in the authorized QoS is treated as a QoS change trigger for charging and CDR-U is sent.