| Protocol | nas | Network | lte |
|---|---|---|---|
| Spec | 3GPP TS 24.301 | Spec Section | 6.5.2, 8.3.21 |
| Direction | MME to UE | Message Type | ESM signaling |
| Full message name | LTE PDN Disconnect Reject |
|---|---|
| Protocol | NAS |
| Technology | LTE |
| Direction | MME to UE |
| Interface | N1 over LTE access / S1-MME control path |
| Signaling bearer / channel | NAS signaling / Sent as the failure branch of a PDN Disconnect Request procedure. |
| Typical trigger | Triggered when the network does not accept the requested PDN disconnect. |
| Main purpose | Returns the ESM cause that explains why the requested PDN release was not accepted. |
| Main specification | 3GPP TS 24.301, 6.5.2, 8.3.21 |
| Release added | Release 8 |
| Procedures where used | UE Requested PDN Disconnect Procedure |
| Related timers | T3492 |
| Related cause values | ESM cause |
PDN Disconnect Reject is the LTE NAS session-management message the network sends when it refuses the UE's request to release a PDN connection.
Returns the ESM cause that explains why the requested PDN release was not accepted.
PDN Disconnect Reject means the network refused to release the PDN connection the UE asked to remove.
Call flow position: Network reject message used when the requested PDN release cannot be accepted.
Typical state: The PDN connection remains active because the release request failed.
Preconditions:
Next likely message: Later retry or continued service on the same PDN
Previous message(s): PDN Disconnect Request
Next message(s): Later retry or continuing service on the same PDN
Security context: Protected by the active NAS security context because it returns a decision about live PDN and bearer state.
PDN Disconnect Reject
ESM cause
Protocol configuration options OPTIONAL
Extended protocol configuration options OPTIONAL
Read the ESM cause first because it explains why the PDN release failed.
PDN Disconnect Reject
Protocol discriminator: EPS session management
EPS bearer identity: 0
Procedure transaction identity: 7
Message type: PDN Disconnect Reject
ESM cause: request rejected, unspecified
| IE | Required | Description |
|---|---|---|
ESM cause | Yes | Explains why the network rejected the requested PDN disconnect. |
Protocol configuration options | Optional | May carry additional protocol-side detail related to the reject decision. |
ESM causeExplains why the network rejected the requested PDN disconnect.
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.
Protocol configuration optionsMay carry additional protocol-side detail related to the reject decision.
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 request may have ended in PDN Disconnect Reject.
What to inspect: Check the ESM cause and whether later activity continues on the same PDN.
Next step: Treat the branch as a failed PDN release instead of a partial bearer teardown.
It is the network message that rejects a UE-requested PDN disconnect and returns the reason as ESM cause.
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.