SIP 199 Early Dialog Terminated vs 606 Not Acceptable
SIP 199 (Early Dialog Terminated) is a 1xx Provisional response, while 606 (Not Acceptable) 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, 606 means that the user's agent was contacted successfully but some aspects of the session description (SDP) are not acceptable. Unlike 488, this is a global failure — no other server can satisfy this request.
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 user's agent was contacted successfully but some aspects of the session description (SDP) are not acceptable. Unlike 488, this is a global failure — no other server can satisfy this request.
Когда вы это видите
When the callee definitively cannot accept any of the offered media types or codecs. Different from 488 which is location-specific.
Как исправить
Check the Warning header or response body for which session parameters are unacceptable. Modify the SDP offer to use compatible codecs and media types.
Ключевые различия
199 is a 1xx Provisional response, while 606 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 606: The user's agent was contacted successfully but some aspects of the session description (SDP) are not acceptable. Unlike 488, this is a global failure — no other server can satisfy this request.
You encounter 199 when in forked call scenarios when one of the forked branches is cancelled because another branch was answered.
You encounter 606 when when the callee definitively cannot accept any of the offered media types or codecs. Different from 488 which is location-specific.
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 606 (Not Acceptable): Check the Warning header or response body for which session parameters are unacceptable. Modify the SDP offer to use compatible codecs and media types.