Messages LTE NAS LTE GUTI Reallocation Complete NAS LTE UE to MME 3GPP TS 24.301
LTE GUTI Reallocation Complete GUTI Reallocation Complete is the LTE NAS message the UE sends to confirm that it accepted and stored the new GUTI.
Message Fact Sheet Full message name LTE GUTI Reallocation Complete Protocol NAS Technology LTE Direction UE to MME Interface N1 over LTE access / S1-MME control path Signaling bearer / channel NAS signaling / Sent immediately after GUTI Reallocation Command in the same secure NAS branch. Typical trigger Triggered when the UE receives GUTI Reallocation Command and stores the new identity. Main purpose Closes the GUTI refresh branch so the network can trust that later LTE NAS procedures will use the new temporary identity. Main specification 3GPP TS 24.301, 8.2.17 Release added Release 8 Procedures where used GUTI Reallocation Procedure
What is LTE GUTI Reallocation Complete in simple terms? GUTI Reallocation Complete is the LTE NAS message the UE sends to confirm that it accepted and stored the new GUTI.
Closes the GUTI refresh branch so the network can trust that later LTE NAS procedures will use the new temporary identity.
Why this message matters GUTI Reallocation Complete is the UE saying it accepted the new temporary identity.
Where this message appears in the call flow Attach-based identity refresh completion After the UE stores the new GUTI, it confirms the identity update with GUTI Reallocation Complete. Call flow position: UE confirmation message after the network refreshed the temporary identity in a secure attach-related branch.
Typical state: The UE remains registered and only confirms that the identity update succeeded.
Preconditions:
The UE received GUTI Reallocation Command. Next likely message: Later NAS procedures using the new GUTI
Tracking area update identity refresh completion The complete message closes the GUTI refresh branch and lets later NAS procedures use the new identity. Call flow position: UE confirmation message after a TAU-related identity refresh.
Typical state: The UE stays registered and only closes the GUTI replacement branch.
Preconditions:
The MME sent GUTI Reallocation Command during or after TAU handling. Next likely message: Later registered-state NAS activity
Call flow position Previous message(s): GUTI Reallocation Command
Next message(s): Later NAS procedures using the new GUTI
Message direction and transport Sender and receiver: UE to MME
Interface: N1 over LTE access / S1-MME control path
Domain: Core-side EPS mobility management signaling that completes a GUTI refresh.
Signaling bearer: NAS signaling
Logical channel: Sent immediately after GUTI Reallocation Command in the same secure NAS branch.
Transport / encapsulation: EPS NAS message sent by the UE to acknowledge the new temporary identity.
Security context: Protected by the active NAS security context because it confirms sensitive identity replacement.
Message Structure Overview GUTI Reallocation Complete is the UE confirmation that the identity refresh branch finished. ASN.1 Message Syntax for LTE GUTI Reallocation Complete GUTI Reallocation Complete
How to read this message syntax This NAS message is structurally simple. The real value is procedural: it closes the GUTI update branch.
LTE GUTI Reallocation Complete - Example Dump GUTI Reallocation Complete
Protocol discriminator: EPS mobility management
Security header type: Integrity protected and ciphered
Message type: GUTI Reallocation Complete
How to read this dump If this message is missing, the MME may retransmit or treat the identity refresh branch as incomplete. What to check in logs and traces Confirm that GUTI Reallocation Command appears immediately before this message. Check that later NAS procedures use the new temporary identity. Common Issues and Troubleshooting The network retransmits identity refresh signaling. Likely cause: GUTI Reallocation Complete may be missing or not received.
What to inspect: Check the command-complete pair and later identity usage.
Next step: Decide whether the UE stored the new GUTI but failed to confirm it, or whether the branch failed earlier.
LTE / 5G / Variant Comparison Compared with GUTI Reallocation Command The command carries the new identity. The complete message is the UE acknowledgment.
FAQ What is GUTI Reallocation Complete in LTE? It is the UE message that confirms it accepted and stored the new GUTI.
Why is it useful in troubleshooting? Because it tells you whether the temporary-identity refresh branch actually completed.
Use This Reference in Practice Decode this message with the 3GPP Decoder , inspect the related message database , or open the matching call flow to see where this signaling step fits in the full procedure.
