SIP 199 Early Dialog Terminated vs 504 Server Time-out
SIP 199 (Early Dialog Terminated) is a 1xx Provisional response, while 504 (Server Time-out) is a 5xx Server 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, 504 means that the server did not receive a timely response from an external server it accessed while attempting to process the request. Different from 408 (client timeout).
Описание
A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
Когда вы это видите
In forked call scenarios when one of the forked branches is cancelled because another branch was answered.
Как исправить
No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully.
Описание
The server did not receive a timely response from an external server it accessed while attempting to process the request. Different from 408 (client timeout).
Когда вы это видите
When a proxy's request to a downstream server times out. The proxy itself is working, but the next hop is unresponsive.
Как исправить
Check the downstream server's availability. Verify DNS resolution for the next-hop domain. Consider adjusting transaction timeout values.
Ключевые различия
199 is a 1xx Provisional response, while 504 is a 5xx Server 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 504: The server did not receive a timely response from an external server it accessed while attempting to process the request. Different from 408 (client timeout).
You encounter 199 when in forked call scenarios when one of the forked branches is cancelled because another branch was answered.
You encounter 504 when when a proxy's request to a downstream server times out. The proxy itself is working, but the next hop is unresponsive.
Когда что использовать
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 504 (Server Time-out): Check the downstream server's availability. Verify DNS resolution for the next-hop domain. Consider adjusting transaction timeout values.