[Conditional] old AMF to new AMF: Response to Namf_Communication_UEContextTransfer (SUPI, UE Context in AMF (as per Table 220.127.116.11.2-1)) or UDSF to new AMF: Nudsf_Unstructured Data Management_Query(). The old AMF may start an implementation specific (guard) timer for the UE context.
If the UDSF was queried in step 4, the UDSF responds to the new AMF for the Nudsf_Unstructured Data Management_Query invocation with the related contexts including established PDU Sessions, the old AMF includes SMF information DNN, S-NSSAI(s) and PDU Session ID, active NGAP UE-TNLA bindings to N3IWF, the old AMF includes information about the NGAP UE-TNLA bindings. If the Old AMF was queried in step 4, Old AMF responds to the new AMF for the Namf_Communication_UEContextTransfer invocation by including the UE's SUPI and UE Context.
If old AMF holds information about established PDU Session(s), the old AMF includes SMF information, DNN(s), S-NSSAI(s) and PDU Session ID(s).
If old AMF holds information about active NGAP UE-TNLA bindings to N3IWF, the old AMF includes information about the NGAP UE-TNLA bindings.
If old AMF fails the integrity check of the Registration Request NAS message, the old AMF shall indicate the integrity check failure.
If old AMF holds information about AM Policy Association, the old AMF includes the information about the AM Policy Association including the policy control request trigger and PCF ID. In the roaming case, V-PCF ID and H-PCF ID are included.
NOTE 5: When new AMF uses UDSF for context retrieval, interactions between old AMF, new AMF and UDSF due to UE signaling on old AMF at the same time is implementation issue.