SIP 199 Early Dialog Terminated vs 607 Unwanted
SIP 199 (Early Dialog Terminated) is a 1xx Provisional response, while 607 (Unwanted) is a 6xx Global Failure response. 199 indicates that a UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs. In contrast, 607 means that the called party did not want this call from the calling party. This response is used for robocall and spam call blocking.
Description
A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
When You See It
In forked call scenarios when one of the forked branches is cancelled because another branch was answered.
How to Fix
No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully.
Description
The called party did not want this call from the calling party. This response is used for robocall and spam call blocking.
When You See It
When the callee's system identifies the call as spam or unwanted. Used in STIR/SHAKEN call verification frameworks.
How to Fix
If you are a legitimate caller being blocked as spam, ensure your STIR/SHAKEN attestation level is 'A' (full attestation). Contact the callee through alternative means.
Key Differences
199 is a 1xx Provisional response, while 607 is a 6xx Global Failure response.
SIP 199: A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
SIP 607: The called party did not want this call from the calling party. This response is used for robocall and spam call blocking.
You encounter 199 when in forked call scenarios when one of the forked branches is cancelled because another branch was answered.
You encounter 607 when when the callee's system identifies the call as spam or unwanted. Used in STIR/SHAKEN call verification frameworks.
When to Use Which
For 199 (Early Dialog Terminated): No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully. For 607 (Unwanted): If you are a legitimate caller being blocked as spam, ensure your STIR/SHAKEN attestation level is 'A' (full attestation). Contact the callee through alternative means.