B.15 Handling of a FLUS session

29.5143GPP5G SystemPolicy Authorization ServiceRelease 18Stage 3TS

If the P-CSCF receives a SIP request that requires provisioning of a service information to the PCF, the "FLUS" feature is supported and an SDP attribute "a=label:flus…" is included in one or more of the received SDP media descriptions, the P-CSCF shall provide the string after "a=label:" starting with "flus" within the "flusId" attribute for each affected media components within the "medComponents" attribute in the corresponding Npcf_PolicyAuthorization service operation towards the PCF.

NOTE: During the first interaction with the PCF, the P-CSCF does not know if the "FLUS" feature is supported by the PCF. In this case the P-CSCF will include the information as if the feature is supported.

If additionally the P-CSCF receives the "a=3gpp-qos-hint" media-level SDP attribute in the SIP request, the P-CSCF shall provide the PCF with the "desMaxLatency" attribute and/or "desMaxLoss" attribute as described in 3GPP TS 29.513 [7], clause 7.2.3.

Upon receiving the information from the P-CSCF and if the "FLUS" feature is supported, the PCF shall derive the QoS information as described in 3GPP TS 29.513 [7], clause 7.3.3.