This clause describes how an Edge Computing related AF may send guidance to PCF determination of proper URSP rules to send to the UE.
An AF related with Edge computing may need to guide PCF determination of proper URSP rules. The guidance sent by the AF may apply to any UE or to a set of UE(s) e.g. identified by a Group Id. The AF may belong to the operator or to a third party.
An AF may deliver such guidance to the PCF via application guidance for URSP rules determination mechanisms defined in clause 220.127.116.11 of TS 23.502. This mechanism is defined only to deliver the guidance to a PCF of the HPLMN of the UE.
The PCF may use the AF guidance received from different AFs, UE subscription data and local operator policy to determine the URSP rules to send to a UE. If received guidance information is not consistent with UE subscription data, or the local operator policy do not allow the specific S-NSSAI and DNN provided by the AF guidance, the corresponding AF guidance shall not be used to determine URSP rules.
Application traffic descriptor from the application guidance is used to set the URSP Traffic Descriptor (e.g. Destination FQDNs or a regular expression in the Domain descriptor), and the PCF determines the URSP rules precedence in the URSP rule (defined in TS 23.503Table 18.104.22.168-2);
Route selection parameter from the application guidance is used to set a Route Selection Descriptor as follows:
DNN and S-NSSAI from the Route selection parameter from the application guidance are used to set the DNN selection, Network Slice selection components in the Route Selection Descriptor of the URSP rule, respectively (defined in TS 23.503Table 22.214.171.124-3) based on the UE subscription data;
Route selection precedence from the application guidance is used to set the Route Selection Descriptor Precedence in the Route Selection Descriptor (defined in TS 23.503Table 126.96.36.199-3);
The spatial validity condition for the Route selection precedence from the application guidance if any are used to set the Location Criteria in the Route Selection Descriptor of the URSP rule (defined in TS 23.503Table 188.8.131.52-3).
URSP rules based on AF guidance should not be set as the URSP rules with the "match all" traffic descriptor.