Content for TS 29.591 Word version: 19.0.0

4.7 Nnef_UEId Service 4.7.1 Service Description 4.7.1.1 Overview 4.7.1.2 Service Architecture 4.7.1.3 Network Functions 4.7.2 Service Operations 4.7.2.1 Introduction 4.7.2.2 Nnef_UEId_Get service operation

4.7 Nnef_UEId Service |R18| p. 41

4.7.1 Service Description p. 41

4.7.1.1 Overview p. 41

The Nnef_UEId service is provided by the Network Exposure Function (NEF). This service allows:

The NF service consumer (e.g., V-NEF) providing the external UE identifier to fetch the internal UE identifier used for e.g., the V-NEF to fetch the SUPI from the H-NEF for the roaming UE under the roaming agreement with the roaming partner(s).
The NF service consumer (e.g., GMLC) to retrieve the UE ID mapping information.

4.7.1.2 Service Architecture p. 41

The 5G System Architecture is defined in TS 23.501.

The Nnef_UEId service is part of the Nnef service-based interface exhibited by the Network Exposure Function (NEF).

Known consumer of the Nnef_UEId service is:

Visited Network Exposure Function (V-NEF)
Gateway Mobile Location Centre (GMLC)

Reproduction of 3GPP TS 29.591, Fig. 4.7.1.2-1: Reference Architecture for the Nnef_UEId Service; SBI representation

Figure 4.7.1.2-1: Reference Architecture for the Nnef_UEId Service; SBI representation

Reproduction of 3GPP TS 29.591, Fig. 4.7.1.2-2: Reference Architecture for the Nnef_UEId Service: reference point representation

Figure 4.7.1.2-2: Reference Architecture for the Nnef_UEId Service: reference point representation

4.7.1.3 Network Functions p. 42

4.7.1.3.1 Network Exposure Function (NEF) p. 42

The Network Exposure Function (NEF) allows:

The NF service consumer (e.g., V-NEF) providing the external UE identifier to fetch the internal UE identifier from the H-NEF for the roaming UE under the roaming agreement with the roaming partner(s).
The NF service consumer (e.g., GMLC) to retrieve the UE ID mapping information.

4.7.1.3.2 NF Service Consumers p. 42

The known NF service consumers are as follows:

The Visited Network Exposure Function (V-NEF):

providing the external UE identifier to fetch the internal UE identifier from the H-NEF for the roaming UE under the roaming agreement with the roaming partner(s).

The Gateway Mobile Location Centre (GMLC):

providing the Application Layer ID to fetch the GPSI of a UE, or vice versa.

4.7.2 Service Operations p. 43

4.7.2.1 Introduction p. 43

The service operations defined for the Nnef_UEId Service are shown in Table 4.7.2.1-1.

Table 4.7.2.1-1: Nnef_UEId Service Operations

Service Operation Name	Description	Initiated by
Nnef_UEId_Get	This service operation is either: used by the NF service consumer (e.g., V-NEF) providing the external UE identifier to fetch the internal UE identifier from the NEF (e.g., H-NEF) for the roaming UE under the roaming agreement with the roaming partner(s). used by the NF service consumer (e.g., GMLC) to retrieve the UE ID mapping information.	NF service consumer (e.g., V-NEF)

4.7.2.2 Nnef_UEId_Get service operation p. 43

4.7.2.2.1 General p. 43

The Nnef_UEId_Get service operation enables:

The NF service consumer (e.g.,V-NEF) provisioning the external UE identifier to fetch the internal UE identifier from the H-NEF for roaming UE under the roaming agreement with the roaming partner(s).
The NF service consumer (e.g., GMLC) to retrieve the UE ID mapping information.

The following procedure using the Nnef_UEId_Get service operation is supported:

To fetch the internal UE identifier for the roaming UE.
To retrieve UE ID mapping information.

4.7.2.2.2 Fetch internal UE information for roaming UE p. 43

Figure 4.7.2.2.2-1 illustrates the retrieval of internal UE ID for roaming UE.

Reproduction of 3GPP TS 29.591, Fig. 4.7.2.2.2-1: Fetch internal UE information for roaming UE

Figure 4.7.2.2.2-1: Fetch internal UE information for roaming UE

In order to fetch the internal UE information (e.g., UE identifier or UE private IP address) for the roaming UE, the NF service consumer (e.g. V-NEF) shall send an HTTP POST request as shown in step 1 of Figure 4.7.2.2.2-1 targeting the custom operation URI "{apiRoot}/nnef-ueid/<apiVersion>/fetch" to fetch the internal UE identifier according to the provided UeIdReq data type which shall include:

external UE identifier of an individual UE via a "gpsi" attribute; or
UE public IP address via a "uePubIpAddr" attribute.

When receiving the HTTP POST request message, the NEF shall verify the NF service consumer (e.g. V-NEF) whether belong to the roaming partner(s) under roaming agreement.

On success, the NEF shall respond with "200 OK" status code with the message body containing the UeIdInfo data structure in the response body shall include:

internal UE identifier of an individual UE via a "supi" attribute; or
UE private IP address via a "uePvtIpAddr" attribute and optionally with HPLMN DNN and S-NSSAI via a "hPlmnDnnSnssai" attribute.

If the requested internal UE identifier does not exist, the NEF shall respond with "204 No Content" status code.

If the NEF determines the received HTTP POST request needs to be redirected, the NEF shall send an HTTP redirect response as specified in clause 6.10.9 of TS 29.500.

If the NEF cannot successfully fulfil the received HTTP POST request due to an internal error or an error in the HTTP POST request, the NEF shall send an HTTP error response as specified in clause 5.6.7.

4.7.2.2.3 UE ID Mapping Information Retrieval p. 44

Figure 4.7.2.2.3-1 depicts a scenario where the service consumer sends a request to the NEF to request UE ID mapping information (see also TS 23.502).

Reproduction of 3GPP TS 29.591, Fig. 4.7.2.2.3-1: UE ID Mapping Information Retrieval

Figure 4.7.2.2.3-1: UE ID Mapping Information Retrieval

Step 1.

In order to request the retrieval of UE ID mapping information, the service consumer shall send an HTTP POST request to the NEF targeting the URI of the corresponding custom operation (i.e., "UEIDMappingInfoRetrieval"), with the request body including the MapUeIdInfo data structure.

Step 2a.

Upon success, the NEF shall respond with either:

an HTTP "200 OK" status code with the response body containing the requested UE ID mapping information within the MapUeIdInfo data structure; or
an HTTP "204 No Content" status code in case no UE ID mapping information exists for the received input parameters.

Step 2b.

On failure, the appropriate HTTP status code indicating the error shall be returned and appropriate additional error information should be returned in the HTTP POST response body, as specified in clause 5.6.7.