EAP-AKA'-based Authentication Call Flow
This section describes the EAP-AKA'-based Authentication basic call flow.

Step |
Description |
---|---|
1 |
The gNB sends the Registration Request along with SUCI information to the AMF. |
2 |
AMF sends Nnrf_NF_Discovery_Get_request with tgt-nf: AUSF, Routing-indicator, and other parameters to the NRF. |
3 |
The AMF receives Nnrf_NF_Discovery_Response from the NRF. |
4 |
The AMF sends Nausf_UEAuthentication_AuthenticateRequest with SUPI, SUCI, and SN-name to the AUSF. |
5 |
The AMF receives Nausf_UEAuthentication_AuthenticateResponse with type: EAP-AKA’, EAPRequest or AKA' challenge, and link from the AUSF. |
6 |
The AMF sends the Authentication Request (EAP Request or AKA’ challenge, ngKSI, ABBA) to the UE. |
7 |
The AMF receives the Authentication Response with the EAP Response or AKA’ challenge from the UE. |
8 |
AMF sends the Nausf_UEAuthentication_AuthenticateRequest (EapSession) to the AUSF. |
9 |
The AMF receives Nausf_UEAuthentication_AuthenticateResponse (EapSession) from the AUSF. |
10 |
The AMF sends the Authentication Request with EAP Request/ngKSI, ABBA to the UE. |
11 |
The AMF receives the Authentication Response (EAP Response) from the UE. |
12 |
AMF sends the Nausf_UEAuthentication_AuthenticateRequest (EapSession) to the AUSF. |
13 |
The AMF receives the Nausf_UEAuthentication_AuthenticateResponse with EAPSuccess, kseaf, and SUPI from the AUSF. |
14 |
The AMF sends the Security Mode command with EAPSuccess, ngKSI, ABBA to UE. |
15 |
The AMF receives the Security Mode Complete from the UE. |
16 |
The AMF sends the Authentication Reject to the UE for Authentication Failure. |
17 |
The AMF sends Nnrf_NFDiscovery_GetRequest with tgt-nf: UDM, Routing-indicator, and other parameters to the NRF. |
18 |
The AMF receives Nnrf_NFDiscovery_Response from the NRF. |