Subscriber Policy
SMF uses subscriber policy to select the operator policy based on the following options:
-
SUPI range
-
SST (Slice/Service Type)
-
IMSI range
-
GPSI
-
PEI
-
SDT (Slice Differentiator Type)
-
S-NSSAI
-
PLMN ID
-
CC (Charging Characteristics) range
Change in Subscriber Policy configuration can be applied dynamically as it has no impact on the existing sessions. SMF selects the operator policy for the new sessions based on the updated configurations.
For 5G subscribers, SMF allows higher number of virtual DNNs (vDNN) with slice-based vDNN selection. However, when 5G subscribers connect from 4G access network, the slice information is unavailable until SMF fetches the UE subscription data from UDM. In such scenarios, SMF performs initial vDNN selection based on the CC lookup parameter as well. After the subscription data is fetched, the SMF reselects the vDNN based on the slice-id information and uses the new vDNN profile. This approach remains the same for the Wi-Fi calls as well.
SMF provides the flexibility of vDNN selection based on using either Charging Characteristics or slice through the CLI configuration. For more information on the configuration part, see the Configuring Subscriber Policy section.
For details, see the "Configuration-based Control of UDM Messages" and "Configuration-based Control of PCF Messages" sections in the Interfaces Support chapter.
Note | As DNN profile is under the operator policy, the reselection of vDNN profile implies the reselection of operator policy as well. SMF supports the configuration so that the reselection doesn't impact the existing features that are associated to other parameters in operator policy. |