SIP 199 Early Dialog Terminated vs 404 Not Found
SIP 199 (Early Dialog Terminated) is a 1xx Provisional response, while 404 (Not Found) is a 4xx Client 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, 404 means that the user specified in the Request-URI does not exist at the domain. The server has authoritative information that the user does not exist.
Descripción
A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
Cuándo lo verás
In forked call scenarios when one of the forked branches is cancelled because another branch was answered.
Cómo solucionarlo
No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully.
Descripción
The user specified in the Request-URI does not exist at the domain. The server has authoritative information that the user does not exist.
Cuándo lo verás
When calling a number or SIP address that does not exist on the server. Different from 480 (user exists but is temporarily unavailable).
Cómo solucionarlo
Verify the SIP URI or phone number. Check if the user is registered on the correct domain. Ensure the domain is correct.
Diferencias clave
199 is a 1xx Provisional response, while 404 is a 4xx Client 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 404: The user specified in the Request-URI does not exist at the domain. The server has authoritative information that the user does not exist.
You encounter 199 when in forked call scenarios when one of the forked branches is cancelled because another branch was answered.
You encounter 404 when when calling a number or SIP address that does not exist on the server. Different from 480 (user exists but is temporarily unavailable).
Cuándo usar cada uno
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 404 (Not Found): Verify the SIP URI or phone number. Check if the user is registered on the correct domain. Ensure the domain is correct.