| Protocol | nas | Network | 5g |
|---|---|---|---|
| Spec | 3GPP TS 24.501 | Spec Section | 8.2.8 |
| Direction | UE to AMF | Message Type | 5GMM signaling |
| Full message name | 5G NAS - Registration Complete |
|---|---|
| Protocol | NAS |
| Technology | 5G |
| Direction | UE to AMF |
| Interface | N1 |
| Signaling bearer / channel | NAS signaling / Dedicated NAS message, commonly transported via UL Information Transfer on the access side |
| Typical trigger | Sent after the UE receives and accepts Registration Accept. |
| Main purpose | Closes the successful registration exchange and confirms that the UE has stored or applied the context returned in Registration Accept. |
| Main specification | 3GPP TS 24.501, 8.2.8 |
| Release added | Release 15 |
| Procedures where used | 5G Initial Registration, Mobility Registration Update |
| Related timers | T3550 |
Registration Complete is the UE-to-AMF NAS message used to confirm that the UE has accepted the registration context returned by the network.
Closes the successful registration exchange and confirms that the UE has stored or applied the context returned in Registration Accept.
Registration Complete is the UE saying the registration success message was received and accepted.
Call flow position: Final UE confirmation after Registration Accept in a successful registration sequence.
Typical state: UE is entering 5GMM-REGISTERED state.
Preconditions:
Next likely message: Normal service activity or optional follow-on NAS procedures
Call flow position: UE confirmation after the network accepts a mobility or periodic registration update.
Typical state: UE remains registered with refreshed mobility-management context.
Preconditions:
Next likely message: Normal registered-state service behavior
Previous message(s): Registration Accept, DL Information Transfer
Next message(s): Configuration Update Command, PDU Session Establishment Request, Normal registered-state service behavior
Security context: Normally sent after NAS security activation, so engineers usually expect integrity protection and often ciphering.
This message is not typically analyzed as ASN.1 on the wire. It is usually read as a NAS or protocol field structure instead.
Registration Complete is a NAS 24.501 message, not an ASN.1-defined message.
Registration Complete
Extended Protocol Discriminator: 5G Mobility Management
Security Header Type: Integrity protected and ciphered
Message Type: Registration Complete
| IE | Presence | Description |
|---|---|---|
SOR transparent container | Optional | Optional container used when steering of roaming information must be returned by the UE. |
SOR transparent containerOptional container used when steering of roaming information must be returned by the UE.
Presence: Optional
In practice: In practice, compare this field with the original request and with any later release-dependent optional fields so you can see whether the network accepted the same service model the UE asked for.
Likely cause: The UE may have failed while processing the returned registration context or the uplink transport path may have failed.
What to inspect: Check Registration Accept contents, UL Information Transfer, RRC stability, and NAS integrity state.
Next step: Compare with a known-good trace and verify whether the UE resets, sends status, or starts a new registration.
Likely cause: The network may not have received Registration Complete, or the UE may not have retained the returned context.
What to inspect: Check uplink delivery of Registration Complete and the next AMF-side state transition.
Next step: Correlate with NAS retransmission timers and subsequent Registration Request attempts.
It confirms that the UE accepted the context returned in Registration Accept and completes the successful registration exchange.
The UE sends it to the AMF over NAS after processing Registration Accept.
In most successful registration flows, yes. It is normally sent after NAS security is active.
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.