NGAP Messages
NGAP carries N2 signaling between the gNB and AMF in 5G core deployments.
Browse UE context creation, handover coordination, and N2 signaling messages used in 5G call flows.
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All Messages in This Category
This is the full published list for the NGAP category. Use the filter section above for a narrower interactive view.
5G NGAP - AMF Configuration Update
AMF Configuration Update is the NGAP interface-management procedure the AMF uses to refresh AMF-side identity, GUAMI, PLMN and slice support, and control-plane TNL association data at the NG-RAN without touching existing UE contexts.
5G NGAP - Downlink NAS Transport
Downlink NAS Transport is the NGAP message the AMF uses to carry a downlink NAS message toward the UE through the NG-RAN over the N2 interface.
5G NGAP - Error Indication
Error Indication is the NGAP message the receiving node sends when it detects a protocol or semantic error in an incoming message and the problem cannot be reported through the normal unsuccessful outcome defined for that procedure.
5G NGAP - Handover Request
Handover Request is the NGAP message the AMF sends to the target NG-RAN to request preparation of resources for an incoming UE during handover preparation.
5G NGAP - Handover Request Acknowledge
Handover Request Acknowledge is the NGAP message the target NG-RAN sends to the AMF to report the prepared target resources, admitted PDU sessions, failed session items, and the transparent container needed for the later handover command path.
5G NGAP - Handover Required
Handover Required is the NGAP message the source NG-RAN sends to the AMF to request preparation of resources at the target during AMF-mediated mobility procedures.
5G NGAP - Initial Context Setup Failure
Initial Context Setup Failure is the NGAP message the NG-RAN sends to AMF when the Initial Context Setup Request cannot be completed for the UE context or its requested setup state.
5G NGAP - Initial Context Setup Request
Initial Context Setup Request is the NGAP message the AMF sends to NG-RAN to establish UE context, security, and initial PDU session resources after successful NAS entry and core-side authentication steps.
5G NGAP - Initial Context Setup Response
Initial Context Setup Response is the NGAP message the NG-RAN sends to AMF to report successful or partial completion of the Initial Context Setup Request, including per-session setup outcomes.
5G NGAP - NAS Non Delivery Indication
NAS Non Delivery Indication is the NGAP message the NG-RAN sends to the AMF when a downlink NAS message cannot be delivered to the UE.
5G NGAP - NG Reset
NG Reset is the NGAP interface-management message that either the AMF or the NG-RAN can send to reset the whole NG interface or a selected set of UE-associated logical NG-connections after loss of transaction reference state or other failure conditions on N2.
5G NGAP - Paging
Paging is the NGAP message the AMF sends to NG-RAN to trigger UE reachability attempts in one or more tracking areas when the UE is not currently on an active UE-associated N2 signaling connection.
5G NGAP - Path Switch Request
Path Switch Request is the NGAP message the new serving NG-RAN sends to the AMF after successful mobility execution to report the new serving node and deliver per-session downlink NG-U tunnel termination information for one or more PDU session resources.
5G NGAP - Path Switch Request Acknowledge
Path Switch Request Acknowledge is the NGAP message the AMF sends to the new serving NG-RAN to confirm that the path switch completed in the 5GC, provide the per-session uplink tunnel information, return the updated security context, and identify any PDU sessions that were released instead of switched.
5G NGAP - PDU Session Resource Release Command
PDU Session Resource Release Command is the NGAP message the AMF sends to the NG-RAN to request release of already established PDU session resources for a given UE.
5G NGAP - PDU Session Resource Release Response
PDU Session Resource Release Response is the NGAP message the NG-RAN sends to the AMF as a response to the request to release already established PDU session resources for a given UE.
5G NGAP - PDU Session Resource Setup Request
PDU Session Resource Setup Request is the NGAP message the AMF sends to NG-RAN to request Uu and NG-U resources, DRBs, and QoS flow handling for one or more PDU sessions of an already identified UE.
5G NGAP - PDU Session Resource Setup Response
PDU Session Resource Setup Response is the NGAP message the NG-RAN sends to AMF to report which requested PDU session resources were successfully established and which failed.
5G NGAP - Reroute NAS Request
Reroute NAS Request is the NGAP message the AMF sends to NG-RAN when the UE's NAS signaling should be rerouted toward a different AMF selection path.
5G NGAP - UE Context Modification Request
UE Context Modification Request is the NGAP message the AMF sends to NG-RAN to partly modify an already established UE context without rebuilding it from scratch.
5G NGAP - UE Context Modification Response
UE Context Modification Response is the NGAP message the NG-RAN sends to AMF to confirm that requested updates to an already established UE context were processed.
5G NGAP - UE Context Release Command
UE Context Release Command is the NGAP message the AMF sends to NG-RAN to order release of the UE-associated logical NG connection and associated access-side context.
5G NGAP - UE Context Release Complete
UE Context Release Complete is the NGAP message the NG-RAN sends to AMF to confirm that the targeted UE-associated logical NG connection has been released.
5G NGAP - Uplink NAS Transport
Uplink NAS Transport is the NGAP message the NG-RAN uses to carry a subsequent uplink NAS message from the UE toward the AMF over the N2 interface after the initial access is already established.
5G NR - Initial UE Message
NGAP initiating message used by the NG-RAN to transfer the UE's first uplink NAS message to the AMF.