5.1 Introduction

29.5033GPP5G SystemRelease 18Stage 3TSUnified Data Management Services

The UDM offeres the following services via the Nudm interface:

– Nudm_SubscriberDataManagement Service

– Nudm_UEContextManagement Service

– Nudm_UEAuthentication Service

– Nudm_EventExposure Service

– Nudm_ParameterProvision Service

– Nudm_NIDDAuthorization Service

– Nudm_MT Service

– Nudm_ServiceSpecificAuthorization Service

– Nudm_ReportSMDeliveryStatus Service

Table 5.1-1 summarizes the corresponding APIs defined for this specification.

Table 5.1-1: API Descriptions

Service Name	Clause	Description	OpenAPI Specification File	apiName	Annex
Nudm_SubscriberDataManagement	6.1	UDM Subscriber Data Management Service	TS29503_Nudm_SDM.yaml	nudm-sdm	A.2
Nudm_UEContextManagement	6.2	UDM Context Management Service	TS29503_Nudm_UECM.yaml	nudm-uecm	A.3
Nudm_UEAuthentication	6.3	UDM UE Authentication Service	TS29503_Nudm_UEAU.yaml	nudm-ueau	A.4
Nudm_EventExposure	6.4	UDM Event Exposure Service	TS29503_Nudm_EE.yaml	nudm-ee	A.5
Nudm_ParameterProvision	6.5	UDM Parameter Provision Service	TS29503_Nudm_PP.yaml	nudm-pp	A.6
Nudm_NIDDAuthorization	6.6	UDM NIDD Authorization Service	TS29503_Nudm_NIDDAU.yaml	nudm-niddau	A.7
Nudm_MT	6.7	UDM MT Service	TS29503_Nudm_MT.yaml	nudm-mt	A.8
Nudm_ServiceSpecificAuthorization	6.8	UDM Service Specific Authorization Service	TS29503_Nudm_SSAU.yaml	nudm-ssau	A.9
Nudm_ReportSMDeliveryStatus	6.9	UDM Report SM-Delivery Status Service	TS29503_Nudm_RSDS.yaml	nudm-rsds	A.10

All scenarios shown in the following clauses assume that the UDM is stateful and stores information in local memory. However, the UDM may be stateless and stores information externally in the UDR. If so, the stateless UDM makes use of Nudr services as specified in 3GPP TS 29.504 [9] and 3GPP TS 29.505 [10] to retrieve required data from the UDR and store them locally before processing an incoming request. Processing the incoming request may then include updating data in the UDR or subscribing to data change notifications at the UDR by consuming the appropriate Nudr services. After processing the incoming request, the UDM may delete the locally stored data. When data stored in UDR is then shared among the different UDM instances of the same group, as identified by UDM Group ID (see 3GPP TS 23.501 [2], clause 6.2.6), bulk subscriptions, as described in clause 4.15.3.2.4 of 3GPP TS 23.502 [3], are not applicable, i.e. an NF consumer (e.g. NEF) only subscribes towards one of the UDM instances within the group. See Annex B.