| Protocol | nas | Network | 5g |
|---|---|---|---|
| Spec | 3GPP TS 24.501 | Spec Section | 8.2.28 |
| Direction | UE to AMF | Message Type | 5GMM signaling |
| Full message name | 5G NAS - Notification Response |
|---|---|
| Protocol | NAS |
| Technology | 5G |
| Direction | UE to AMF |
| Interface | N1 |
| Signaling bearer / channel | NAS signaling / Dedicated NAS message, commonly transported via UL Information Transfer |
| Typical trigger | Sent after the UE successfully receives and processes Notification from the network. |
| Main purpose | Confirms UE-side reception of the network notification so the surrounding NAS signaling context can continue in an orderly way. |
| Main specification | 3GPP TS 24.501, 8.2.28 |
| Release added | Release 15 |
| Procedures where used | Protected 5GMM signaling, Registration follow-on handling, Service-context notification handling |
Notification Response is the NAS message the UE sends after receiving Notification from the network to acknowledge the NAS indication and let the protected procedure continue.
Confirms UE-side reception of the network notification so the surrounding NAS signaling context can continue in an orderly way.
Notification Response is the UE acknowledging the network's NAS notification.
Call flow position: UE acknowledgement step after Notification during an already established NAS context.
Typical state: The UE has received the NAS indication and confirms it back to the AMF.
Preconditions:
Next likely message: Further protected NAS signaling based on the wider procedure
Call flow position: UE acknowledgement after the network sends a protected NAS notification following registration or service success.
Typical state: The main NAS relationship is active and the notification sub-step is being closed.
Preconditions:
Next likely message: Procedure-specific follow-on NAS handling
Previous message(s): Notification, Protected 5GMM signaling context
Next message(s): Further protected NAS signaling, Configuration Update Command, Procedure continuation
Security context: Usually belongs to an already protected NAS context, so the response should be interpreted together with the security state of the preceding Notification.
This message is not typically analyzed as ASN.1 on the wire. It is usually read as a NAS or protocol field structure instead.
Notification Response follows NAS 24.501 IE structure and is not an ASN.1 message.
Notification Response
Extended Protocol Discriminator: 5G Mobility Management
Security Header Type: Integrity protected and ciphered
Message Type: Notification Response
| IE | Required | Description |
|---|---|---|
No major dedicated payload IE | Optional | The response is mainly procedural acknowledgement, so trace value comes more from timing and protection state than from a large field set. |
No major dedicated payload IEThe response is mainly procedural acknowledgement, so trace value comes more from timing and protection state than from a large field set.
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 not have processed the notification correctly, or the uplink protected NAS response was not delivered.
What to inspect: Check UE logs, uplink NAS transport, and whether the UE remained in the expected mobility-management state.
Next step: Compare against a known-good protected NAS trace and verify that the earlier Notification was valid and decodable.
Likely cause: The notification exchange itself completed, so the root cause is more likely in the follow-on NAS procedure.
What to inspect: Use Notification Response as the boundary point and continue analysis into the next protected NAS messages.
Next step: Move forward in the trace rather than staying on the notification pair.
It acknowledges the earlier Notification from the network so the protected NAS procedure can continue.
Usually no. It is primarily a procedural acknowledgement message.
Because it confirms that the UE received the earlier Notification and that the NAS context was still working at that point.
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.