SIP 181 Call Is Being Forwarded vs 199 Early Dialog Terminated
Both SIP 181 (Call Is Being Forwarded) and 199 (Early Dialog Terminated) belong to the 1xx Provisional category. 181 indicates that a proxy server may send this to indicate that the call is being forwarded to a different set of destinations. Meanwhile, 199 means that a UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
설명
A proxy server may send this to indicate that the call is being forwarded to a different set of destinations.
이 코드를 보게 되는 경우
When the callee has call forwarding enabled and the request is being redirected to another number or device.
해결 방법
No action needed. The call is being redirected. If forwarding is unintended, the callee should update their forwarding settings.
설명
A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
이 코드를 보게 되는 경우
In forked call scenarios when one of the forked branches is cancelled because another branch was answered.
해결 방법
No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully.
주요 차이점
SIP 181: A proxy server may send this to indicate that the call is being forwarded to a different set of destinations.
SIP 199: A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
You encounter 181 when when the callee has call forwarding enabled and the request is being redirected to another number or device.
You encounter 199 when in forked call scenarios when one of the forked branches is cancelled because another branch was answered.
언제 어떤 것을 사용할지
For 181 (Call Is Being Forwarded): No action needed. The call is being redirected. If forwarding is unintended, the callee should update their forwarding settings. For 199 (Early Dialog Terminated): No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully.