| Protocol | ims | Network | 5G and LTE |
|---|---|---|---|
| Spec | RFC 3261 / 3GPP TS 24.229 | Spec Section | SIP 603 Decline global failure response |
| Direction | IMS network -> UE | Message Type | SIP global-failure response |
| Full message name | IMS SIP 603 Decline |
|---|---|
| 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 / Global failure response |
| Typical trigger | The called side or service explicitly declines the request. |
| Main purpose | Provides a global refusal result for the current request attempt. |
| Main specification | RFC 3261 / 3GPP TS 24.229, SIP 603 Decline global failure response |
| Release added | See specification history |
| Procedures where used | IMS Global Session Rejection |
603 Decline means the request was actively refused and should not be retried to other locations for the same attempt.
Provides a global refusal result for the current request attempt.
603 means the request was declined and should not be retried elsewhere for the same attempt.
Previous message(s): IMS SIP INVITE
Next message(s): Procedure stop
Security context: Uses the same protected IMS signaling path as the original request.
SIP/2.0 603 Decline
Via:
From:
To:
Call-ID:
CSeq:
Content-Length: 0
This is SIP response syntax rather than ASN.1.
SIP/2.0 603 Decline
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
| IE | Required | Description |
|---|---|---|
Status-Line | Yes | Shows the 603 global decline code. |
Warning | Optional | Can add extra refusal context. |
Status-LineShows the 603 global decline 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.
WarningCan add extra refusal context.
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 far side or service decided to decline the request outright.
What to inspect: Check whether the response is truly global and whether alternate branches were suppressed.
Next step: Treat 603 as a final refusal for that request attempt.
It means the request was explicitly declined and should not be retried to other locations for the same attempt.
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.