SIP 199 Early Dialog Terminated vs 500 Server Internal Error
SIP 199 (Early Dialog Terminated) is a 1xx Provisional response, while 500 (Server Internal Error) 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, 500 means that the server encountered an unexpected condition that prevented it from fulfilling the request.
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 server encountered an unexpected condition that prevented it from fulfilling the request.
When You See It
When the SIP server has an internal error — database failure, unhandled exception, or resource exhaustion.
How to Fix
Check server logs for the specific error. Common causes include database connectivity issues, configuration errors, or memory exhaustion.
Key Differences
199 is a 1xx Provisional response, while 500 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 500: The server encountered an unexpected condition that prevented it from fulfilling the request.
You encounter 199 when in forked call scenarios when one of the forked branches is cancelled because another branch was answered.
You encounter 500 when when the SIP server has an internal error — database failure, unhandled exception, or resource exhaustion.
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 500 (Server Internal Error): Check server logs for the specific error. Common causes include database connectivity issues, configuration errors, or memory exhaustion.