RRC 5G UE -> gNB 3GPP TS 38.331

5G NR - RRC Reestablishment Complete

RRC Reestablishment Complete is the UE-to-network NR RRC message confirming that reestablishment succeeded and the recovered context is active.

Message Fact Sheet

Protocol	rrc	Network	5g
Spec	3GPP TS 38.331	Spec Section	5.3.7, 6.2.2
Direction	UE -> gNB	Message Type	Connection Recovery

Full message name	5G NR - RRC Reestablishment Complete
Protocol	RRC
Technology	5G
Direction	UE -> gNB
Interface	Uu
Signaling bearer / channel	SRB1 / UL-DCCH
Typical trigger	Used when the UE successfully applies the RRC Reestablishment message.
Main purpose	Confirms successful completion of the reestablishment path so normal protected connected-mode operation can continue.
Main specification	3GPP TS 38.331, 5.3.7, 6.2.2
Release added	Release 15
Procedures where used	RRC Reestablishment, Radio Link Failure Recovery
Related timers	None highlighted
Related cause values	None highlighted

What is RRC Reestablishment Complete in simple terms?

RRC Reestablishment Complete is the UE-to-network NR RRC message confirming that reestablishment succeeded and the recovered context is active.

Confirms successful completion of the reestablishment path so normal protected connected-mode operation can continue.

Why this message matters

RRC Reestablishment Complete tells the network that recovery succeeded.

Where this message appears in the call flow

RRC Reestablishment

Call flow position: Final UE confirmation after successful reestablishment.

Typical state: UE has recovered the RRC context and confirms it.

Preconditions:

The UE received and accepted RRC Reestablishment.

Next likely message: Normal connected-mode signaling or later reconfiguration

Call flow position

Previous message(s): RRC Reestablishment

Next message(s): RRC Reconfiguration, Normal connected signaling

Message direction and transport

Sender and receiver: UE -> gNB

Interface: Uu

Domain: Access-side radio control and recovery confirmation

Signaling bearer: SRB1

Logical channel: UL-DCCH

Transport / encapsulation: Dedicated protected RRC signaling

Security context: Sent after reestablishment has restored the connected signaling context.

Message Structure Overview

The message is mainly a recovery confirmation rather than a heavy configuration message.

ASN.1 for 5G NR - RRC Reestablishment Complete

RRCReestablishmentComplete ::= SEQUENCE {
  criticalExtensions CHOICE {
    rrcReestablishmentComplete RRCReestablishmentComplete-IEs,
    ...
  }
}

How to read this ASN.1

The main value is procedural: this message confirms that the recovery path completed.

Decoded Message Dump

UL-DCCH-Message
  message: rrcReestablishmentComplete

How to read this dump

Once this appears, the reestablishment path has normally succeeded.

Important Information Elements

IE	Required	Description
`lateNonCriticalExtension`	Optional	Extension field for later releases.

Detailed field explanation

`lateNonCriticalExtension`

Extension field for later releases.

Presence: Optional

What to check in logs and traces

Check that RRC Reestablishment happened immediately before this message.
Correlate it with later normal connected-mode signaling.

Common Issues and Troubleshooting

Reestablishment appears accepted but the connection still collapses.

Likely cause: The UE may send the complete, but the recovered context may still be unstable.

What to inspect: Check later reconfiguration, measurement, or failure messages after the complete.

Next step: Treat this as the recovery completion point and investigate what broke next.

Detailed explanation

5G NR - RRC Reestablishment Complete Explained

RRC Reestablishment Complete is a 5G NR RRC message reference page for engineers who need to understand what the message carries, where it fits in the procedure, and what to inspect in traces when behavior does not match expectation.

RRC Reestablishment Complete is the UE-to-network NR RRC message confirming that reestablishment succeeded and the recovered context is active. Confirms successful completion of the reestablishment path so normal protected connected-mode operation can continue.

What is RRC Reestablishment Complete in simple terms?

RRC Reestablishment Complete is the uplink NR RRC message the UE sends to the network when this specific procedure step needs to be requested, reported, or confirmed.

Confirms successful completion of the reestablishment path so normal protected connected-mode operation can continue.

Why this message matters

it directly affects RRC Reestablishment, Radio Link Failure Recovery
Reestablishment appears accepted but the connection still collapses
Used when the UE successfully applies the RRC Reestablishment message

Where this message appears in the call flow

RRC Reestablishment Complete is typically seen during RRC Reestablishment. Engineers usually read it together with the messages just before and just after it so they can tell whether the procedure is progressing normally or drifting into a fallback or failure path.

The UE is usually in UE has recovered the RRC context and confirms it when engineers evaluate this message in traces. In the main procedure context, it appears final UE confirmation after successful reestablishment. Before this message appears, the important preconditions are The UE received and accepted RRC Reestablishment..

Simplified sequence:

UE                       gNB / Network
|                        |
|<-- RRC Reestablishment -----------|
|--- RRC Reestablishment Complete ----------->|
|<-- RRC Reconfiguration -----------|

Message direction and transport

sender: UE
receiver: gNB
interface: Uu
signaling bearer: SRB1
signaling channel: UL-DCCH
transport type: Dedicated protected RRC signaling
domain: Access-side radio control and recovery confirmation
security context: Sent after reestablishment has restored the connected signaling context.

Important Information Elements

IE	Why it matters
`lateNonCriticalExtension`	Extension field for later releases.

Example message dump

UL-DCCH-Message
  message: rrcReestablishmentComplete

How to read this dump

Once this appears, the reestablishment path has normally succeeded.

FAQ

What does RRC Reestablishment Complete mean?

It means the UE successfully completed the reestablishment procedure.

Summary

RRC Reestablishment Complete is the UE-to-network NR RRC message confirming that reestablishment succeeded and the recovered context is active.

Advanced Engineer Notes

This message is easy to miss in traces, but it clearly separates accepted recovery from failed recovery.

Related message pages

Related Procedures

5G RRC Reestablishment

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.