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.
คำอธิบาย
A proxy server may send this to indicate that the call is being forwarded to a different set of destinations.
เมื่อคุณพบเห็น
When the callee has call forwarding enabled and the request is being redirected to another number or device.
วิธีแก้ไข
No action needed. The call is being redirected. If forwarding is unintended, the callee should update their forwarding settings.
คำอธิบาย
A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
เมื่อคุณพบเห็น
In forked call scenarios when one of the forked branches is cancelled because another branch was answered.
วิธีแก้ไข
No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully.
ความแตกต่างหลัก
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.
ควรใช้อันไหนเมื่อไร
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.