How it Works

The SMF receives the non-standard and standard QCIs in QoS from PCF through SmPolicyCreateResponse, SmPolicyUpdateResponse, or SmPolicyUpdateNotify message.

If the PCF does not send the session rule information or if the PCF sends an invalid QCI value, the SMF uses the UDM-provided non-standard QCI value and processes the QCI information in the same manner as sent by PCF. If neither PCF nor UDM sends the non-standard QCI information, the SMF uses the QCI information locally configured within QoS profile. For configuration details, see the Configuring QoS Parameters section.

When the PCF sends a PCC rule with a non-standard QCI, the SMF creates a GBR flow if the (UL and DL) GBR QoS information is available in the associated QoS-Descriptor. Otherwise, the SMF creates a non-GBR flow.

For the default session rule, the SMF assumes it as a non-GBR flow irrespective of the non-standard QCI information it receives from PCF.

The SMF initiates the session establishment or modification procedure towards RAN or UE, and communicates the same QCI information on N1, N2, N4, and S5 interfaces.

Note

The SMF does not handle the QoS Characteristics sent by PCF for a non-standard QCI.

If a discrepancy or an ambiguity arises in the QCI input from PCF, the SMF performs the following validations:

  • The SMF checks if the QCI value is ranging from 1 through 255. The SMF does not handle any non-standard QCI value that does not fall within the specified range.

  • When the PCF sends session rule and PCC rule with the same binding parameters and non-standard QCI along with GBR UL and DL information as shown in the following example, the SMF rejects the “PccRule1” PCC rule.

    sessRule1=>AuthDefQos{arp1, qci128}+ authSessAmbr{UL=20mbps,DL=20mbps}
    PccRule1=>QosDesc{arp1, qci128, gbrUL=10mbps, gbrDL=10mbps}