| Protocol | nas | Network | lte |
|---|---|---|---|
| Spec | 3GPP TS 24.301 | Spec Section | Release 18 generic NAS transport message definition |
| Direction | UE to MME | Message Type | EMM signaling |
| Full message name | LTE Uplink Generic NAS Transport |
|---|---|
| Protocol | NAS |
| Technology | LTE |
| Direction | UE to MME |
| Interface | N1 over LTE access / S1-MME control path |
| Signaling bearer / channel | NAS signaling / Used in generic transport branches when the UE sends a non-SMS NAS payload toward the network. |
| Typical trigger | Triggered when the UE needs to send a generic NAS payload through the control plane. |
| Main purpose | Transports generic payload or control-plane container content that does not belong to the SMS-only uplink NAS transport branch. |
| Main specification | 3GPP TS 24.301, Release 18 generic NAS transport message definition |
| Release added | Release 13 |
| Procedures where used | Generic NAS Transport Procedure, Control Plane CIoT EPS Optimization |
| Related timers | T3447 |
Uplink Generic NAS Transport is the LTE NAS message the UE sends when it needs to carry a generic payload through the EMM transport branch.
Transports generic payload or control-plane container content that does not belong to the SMS-only uplink NAS transport branch.
Uplink Generic NAS Transport is the UE-side LTE NAS message used to carry a generic payload through the EMM transport branch.
Call flow position: UE-originated transport message used to send a generic payload toward the MME.
Typical state: The EMM branch is active and the payload uses generic NAS transport.
Preconditions:
Next likely message: Downlink Generic NAS Transport or higher-layer continuation
Call flow position: UE transport message used when a CIoT control-plane branch carries generic payload without a normal user-plane setup.
Typical state: The UE is intentionally using generic transport on the control plane.
Preconditions:
Next likely message: Downlink Generic NAS Transport or service completion
Previous message(s): Control Plane Service Request, Service Accept
Next message(s): Downlink Generic NAS Transport
Security context: Usually protected because it appears in an established EMM context.
Uplink Generic NAS Transport
Generic message container
Additional information OPTIONAL
Read the generic message container first and then identify the wider generic or CIoT transport branch.
Uplink Generic NAS Transport
Protocol discriminator: EPS mobility management
Security header type: Integrity protected and ciphered
Message type: Uplink Generic NAS Transport
Generic message container: generic payload
| IE | Required | Description |
|---|---|---|
Generic message container | Yes | Carries the generic payload sent by the UE through NAS transport. |
Generic message containerCarries the generic payload sent by the UE through NAS transport.
Presence: Required
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 branch may be using Uplink Generic NAS Transport on the control plane.
What to inspect: Check the generic message container and the surrounding CIoT or generic transport context.
Next step: Treat the branch as intentional generic NAS transport before blaming missing bearer setup.
It is the UE-side LTE NAS message used to carry a generic payload through the EMM transport branch.
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.