5.8.2.24 Support of throughput advice signalling

Support of throughput advice signaling is an optional feature and refers to the support of the IETF SCONE Protocol (draft-ietf-scone-protocol-04 [224]) that enables the UPF to provide throughput advice (i.e. operator-applied data rate limit information) to an application to adapt its data rate.

The PCF, based on the AF input and/or operator policies, generates PCC rules including the SCONE Marking Indication and optionally, a SCONE Throughput Advice as defined in clause 6.1.3.32 of TS 23.503 [45].

NOTE 1: In the absence of AF input, SCONE-capable traffic flow(s) are identified based on operator configuration, e.g. using FQDN, IP address range, DNN/SNSSAI. SCONE-capable traffic flow is a traffic flow authorized to receive throughput advice.

Based on the received PCC rule or local configuration, the SMF instructs the UPF to detect SCONE packets in the SCONE traffic flow(s) corresponding to the PDR. The UPF updates the Rate Signal field, as specified in IETF SCONE Protocol (draft-ietf-scone-protocol-04 [224]), in the SCONE packets of the traffic matching the PDR, according to the associated SCONE Throughput Advice received from the SMF or based on local configuration, if not provided.

NOTE 2: Rate limit enforcement for the SCONE traffic flow(s) at UPF is performed according to operator policy.

Based on request received by PCF for application detection of SCONE traffic flows as specified in clause 6.1.3.32 of TS 23.503 [45], the SMF may configure the UPF to report the SCONE traffic flow information.

Alternatively, the UPF may be configured to detect SCONE traffic flows and update the Rate Signal field in the SCONE packets based on local configuration.

NOTE 3: The application detection for SCONE traffic flows is up to UPF implementation and as specified in IETF SCONE Protocol (draft-ietf-scone-protocol-04 [224]).

NOTE 4: Handling of Payload Headers can be used instead to configure a UPF for support of IETF Standard Communication with Network Elements (SCONE) Protocol (draft-ietf-scone-protocol-04 [224]). According to clause 5.6.17, updates in the SCONE packets as well as notifications upon detection of SCONE-capable flows are part of the UPF configuration. The reference to the UPF configuration is determined prior to enabling the feature for SCONE.