SIP 199 Early Dialog Terminated vs 488 Not Acceptable Here
SIP 199 (Early Dialog Terminated) is a 1xx Provisional response, while 488 (Not Acceptable Here) 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, 488 means that the request was understood but the session description (SDP) is not acceptable. The response may contain a list of acceptable media parameters.
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 request was understood but the session description (SDP) is not acceptable. The response may contain a list of acceptable media parameters.
Когда вы это видите
When codec negotiation fails — the callee cannot handle any of the codecs offered in the SDP. Common in interop scenarios.
Как исправить
Check the Warning header or SDP in the response for acceptable parameters. Add compatible codecs (e.g., G.711 as a fallback) to your offer.
Ключевые различия
199 is a 1xx Provisional response, while 488 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 488: The request was understood but the session description (SDP) is not acceptable. The response may contain a list of acceptable media parameters.
You encounter 199 when in forked call scenarios when one of the forked branches is cancelled because another branch was answered.
You encounter 488 when when codec negotiation fails — the callee cannot handle any of the codecs offered in the SDP. Common in interop scenarios.
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 488 (Not Acceptable Here): Check the Warning header or SDP in the response for acceptable parameters. Add compatible codecs (e.g., G.711 as a fallback) to your offer.