Section: 5.8.2.4.2 Traffic Detection Information
Content: The SMF controls the traffic detection at the UP function by providing detection information for every PDR. For IPv4 or IPv6 or IPv4v6 PDU Session type, detection information is a combination of: - CN tunnel info. - Network instance. - QFI. - IP Packet Filter Set as defined in clause 5.7.6.2. - Application Identifier: The Application Identifier is an index to a set of application detection rules configured in UPF. - FQDN Filter for DNS Query message. For Ethernet PDU Session type, detection information is a combination of: - CN tunnel info. - Network instance. - QFI. - Ethernet Packet Filter Set as defined in clause 5.7.6.3. In this Release of the specification for Unstructured PDU Session Type, the UPF does not perform-QoS Flow level traffic detection for QoS enforcement. Traffic detection information sent by the SMF to the UPF for a PDU Session may be associated with Network instance for detection and routing of traffic over N6. In the case of IP PDU Session Type, Network Instances can, e.g. be used by the UPF for traffic detection and routing in the case of different IP domains or overlapping IP addresses. In the case of Ethernet PDU Session Type, different Network Instances can e.g. be configured in the UPF with different ways to handle the association between N6 and the PDU Sessions. Based on SMF instructions, UPF may identify the PDU Sets, according to the Protocol Description in PDR, to derive the PDU Set Information for DL traffics and send it to RAN via DL GTP-U header of each PDU identified as belonging to a PDU Set. The PDU Set Information, is described in clause 5.37.5. The PDU Set identification can be done by UPF implementation or by detecting RTP/SRTP header or payload. The details of the RTP/SRTP headers, header extensions and/or payloads used to identify PDU Sets are defined in TS 26.522[ 5G Real-time Media Transport Protocol Configurations ]  [179].