LTE Bearer Resource Allocation Reject

Message Fact Sheet

Protocol	nas	Network	lte
Spec	3GPP TS 24.301	Spec Section	6.5.3, 8.3.7
Direction	MME to UE	Message Type	ESM signaling

Full message name	LTE Bearer Resource Allocation 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 reject branch of a bearer resource allocation procedure.
Typical trigger	Triggered when the network does not accept the UE-requested dedicated bearer resource.
Main purpose	Returns the ESM cause that explains why the requested bearer resource was not allocated.
Main specification	3GPP TS 24.301, 6.5.3, 8.3.7
Release added	Release 8
Procedures where used	Bearer Resource Allocation Procedure
Related timers	T3480
Related cause values	ESM cause

What is LTE Bearer Resource Allocation Reject in simple terms?

Bearer Resource Allocation Reject is the LTE NAS message the network sends when it refuses the UE's request for a dedicated bearer resource.

Returns the ESM cause that explains why the requested bearer resource was not allocated.

Why this message matters

Bearer Resource Allocation Reject means the network refused to allocate the dedicated bearer resource the UE asked for.

Where this message appears in the call flow

Requested dedicated bearer allocation rejected

LTE flow showing Bearer Resource Allocation Reject after a dedicated bearer request — If the network does not accept the requested dedicated bearer resource, it answers with Bearer Resource Allocation Reject.

Call flow position: Network reject message used when the UE-requested dedicated bearer cannot be allocated.

Typical state: The default bearer may stay active while the additional resource request fails.

Preconditions:

The UE sent Bearer Resource Allocation Request.

Next likely message: Later retry or service continuation on existing bearers

Policy or subscription-based allocation reject

LTE flow showing Bearer Resource Allocation Reject due to policy or subscription limits — A reject branch usually means the requested bearer resource did not fit current policy, subscription, or network capability.

Call flow position

Previous message(s): Bearer Resource Allocation Request

Next message(s): Later retry or service continuation on existing bearers

Message direction and transport

Sender and receiver: MME to UE

Interface: N1 over LTE access / S1-MME control path

Domain: Core-side EPS session management failure handling for dedicated bearer resource allocation.

Signaling bearer: NAS signaling

Logical channel: Sent as the reject branch of a bearer resource allocation procedure.

Transport / encapsulation: EPS NAS ESM message sent by the MME to reject a UE-requested dedicated bearer resource.

Security context: Protected by the active NAS security context.

Message Structure Overview

Bearer Resource Allocation Reject is the failure branch of UE-requested dedicated bearer allocation.

ASN.1 Message Syntax for LTE Bearer Resource Allocation Reject

Bearer Resource Allocation Reject
  ESM cause
  Protocol configuration options       OPTIONAL
  Extended protocol configuration options OPTIONAL

How to read this message syntax

Read the ESM cause first because it explains why the dedicated bearer resource was not granted.

LTE Bearer Resource Allocation Reject - Example Dump

Bearer Resource Allocation Reject
  Protocol discriminator: EPS session management
  EPS bearer identity: 0
  Procedure transaction identity: 9
  Message type: Bearer Resource Allocation Reject
  ESM cause: requested service option not subscribed

How to read this dump

The ESM cause is the key field.

Important Information Elements

IE	Required	Description
`ESM cause`	Yes	Explains why the network rejected the requested bearer resource allocation.
`Protocol configuration options`	Optional	May carry additional configuration-side detail related to the reject.

Detailed field explanation

`ESM cause`

Explains why the network rejected the requested bearer resource allocation.

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 options`

May carry additional configuration-side detail related to the reject.

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.

What to check in logs and traces

Check the earlier bearer resource allocation request.
Inspect the returned ESM cause first.

Common Issues and Troubleshooting

A service path never receives the expected dedicated bearer.

Likely cause: The dedicated-bearer request may have ended in Bearer Resource Allocation Reject.

What to inspect: Check the requested QoS, traffic flow aggregate, and the returned ESM cause.

Next step: Treat the branch as failed resource allocation before blaming activation signaling.

FAQ

What is Bearer Resource Allocation Reject in LTE?

It is the network message that rejects a UE-requested dedicated bearer resource and returns the reason as ESM cause.

Related message pages

Related Procedures

Related Tools

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.