IMS 5G AND LTE IMS network -> UE RFC 3261 / 3GPP TS 24.229

IMS SIP 487 Request Terminated

487 Request Terminated means the original request branch was stopped before normal completion.

Message Fact Sheet

Protocol	ims	Network	5G and LTE
Spec	RFC 3261 / 3GPP TS 24.229	Spec Section	SIP 487 Request Terminated failure response
Direction	IMS network -> UE	Message Type	SIP request-failure response

Full message name	IMS SIP 487 Request Terminated
Protocol	IMS
Technology	5G and LTE
Common deployment	VoNR and VoLTE
Direction	IMS network -> UE
Interface	Gm with onward IMS routing
Signaling bearer / channel	IMS SIP signaling / Final request-failure response
Typical trigger	An INVITE branch was canceled or otherwise terminated before final success.
Main purpose	Closes the original request branch after cancellation or related branch termination.
Main specification	RFC 3261 / 3GPP TS 24.229, SIP 487 Request Terminated failure response
Release added	See specification history
Procedures where used	IMS Session Cancellation

What is IMS SIP 487 Request Terminated in simple terms?

487 Request Terminated means the original request branch was stopped before normal completion.

Closes the original request branch after cancellation or related branch termination.

Why this message matters

487 means the request branch was terminated before normal completion.

Where this message appears in the call flow

IMS Session Cancellation

Call flow position

Previous message(s): IMS SIP CANCEL, IMS SIP INVITE

Next message(s): Transaction cleanup

Message direction and transport

Sender and receiver: IMS network -> UE

Interface: Gm with onward IMS routing

Domain: IMS transaction termination

Signaling bearer: IMS SIP signaling

Logical channel: Final request-failure response

Transport / encapsulation: SIP over UDP, TCP, or TLS

Security context: Uses the same protected IMS signaling path as the original transaction.

Message Structure Overview

487 usually belongs to a request branch that was explicitly stopped before completion.

ASN.1 Message Syntax for IMS SIP 487 Request Terminated

SIP/2.0 487 Request Terminated
Via:
From:
To:
Call-ID:
CSeq:
Content-Length: 0

How to read this message syntax

This is SIP response syntax rather than ASN.1.

IMS SIP 487 Request Terminated - Example Dump

SIP/2.0 487 Request Terminated
Via: SIP/2.0/UDP ue.example.net;branch=z9hG4bK-inv1
From: <sip:alice@example.net>;tag=mo1
To: <sip:bob@example.net>;tag=term1
Call-ID: call-001@example.net
CSeq: 1 INVITE
Content-Length: 0

Important Information Elements

IE	Required	Description
`Status-Line`	Yes	Shows the 487 failure code.
`Call-ID`	Yes	Correlates the terminated branch with the original request.

Detailed field explanation

`Status-Line`

Shows the 487 failure code.

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.

`Call-ID`

Correlates the terminated branch with the original request.

Presence: Required

Common Issues and Troubleshooting

The request fails after cancellation or branch cleanup.

Likely cause: The original request branch was explicitly terminated before final answer.

What to inspect: Check whether CANCEL or forked-branch cleanup happened first.

Next step: Read 487 together with the branch-termination story, not as an isolated failure.

FAQ

What does 487 Request Terminated mean?

It means the original SIP request branch was stopped before it could complete normally.

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.