Subscription Data Management (SDM) Service

The UDM SDM service supports data retrieval of the shared data identified by the received shared data Ids for the following subscription:

• Slice Selection Subscription: The NF service consumer (AMF) sends a request to the UDM to fetch Network Slice Selection Assistance Information (NSSAI) data of the UE.
• Access and Mobility Subscription: The NF service consumer (AMF) sends a request to the UDM to retrieve Access and Mobility Subscription data of the UE. The request contains the UE's identity (/{supi}), the type of the requested information (/am-data) and query parameters (supported-features, plmn-id).
• SMF Selection Subscription: An AMF sends a request to the UDM for SMF selection information for a particular subscriber using the SMF selection subscription data retrieval procedure.
  • Session Management Subscription: An SMF sends a request to the UDM for Session Management subscription data of a particular UE.
  • UE Context In SMF: The UDM can be requested to provide the context of the UE in SMF during times of call recovery (Example: SMF to SMF handover/ AMF recovery etc).
• Subscription to Notification of Data Change Service:
  • The NF service consumer sends a request to UDM to subscribe to data change notification, which contains a callback URI and URI of the monitored resource.
  • UDM maps the request to UDR, which in turn creates the subs-to-notify subscription.
  • UDR monitors the resources and informs UDM when a change is observed in the monitored resource.
  • It also supports modification/deletion of the subscription.

For more information, refer to Subscription Data Management (SDM) Service User configuration parameters in UDM Installation Guide.