Section: 5.37.5.3 Non-homogenous support of PDU set based handling in NG-RAN
Content: By sending at least one PDU Set QoS parameter to the NG-RAN, the SMF requests the NG-RAN to activate PDU Set QoS handling for a given QoS flow and the NG-RAN provides the SMF with an indication of whether the PDU Set based handling is supported. Based on this indication, SMF may activate the PDU Set identification and marking in the PSA UPF. For the mobility procedures that may result in the change of NG-RAN for PDU Set based handling support, the target NG-RAN provides to the SMF with an indication of whether the target NG-RAN node supports PDU Set based handling, as specified in TS 38.413[ NG-RAN; NG Application Protocol (NGAP) ]  [34]. Based on the target NG-RAN indication, the SMF may, upon completion of the mobility procedure, initiate the PDU Session modification procedure to provide PDU Set QoS parameters to NG-RAN and may configure the PSA UPF to activate/deactivate the PDU Set identification and marking. In the case where the PSA UPF identifies and marks PDUs with PDU Set information in GTP-U header, it shall start doing so from a complete PDU Set.