SIP 199 Early Dialog Terminated vs 202 Accepted
SIP 199 (Early Dialog Terminated) is a 1xx Provisional response, while 202 (Accepted) is a 2xx Success 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, 202 means that the request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests.
Descrição
A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
Quando você o vê
In forked call scenarios when one of the forked branches is cancelled because another branch was answered.
Como corrigir
No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully.
Descrição
The request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests.
Quando você o vê
After sending a REFER request for call transfer. The transfer target acknowledges receipt but hasn't completed the transfer yet.
Como corrigir
Wait for a NOTIFY to learn the outcome of the referred action. If no NOTIFY arrives, check subscription state and network connectivity.
Diferenças principais
199 is a 1xx Provisional response, while 202 is a 2xx Success 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 202: The request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests.
You encounter 199 when in forked call scenarios when one of the forked branches is cancelled because another branch was answered.
You encounter 202 when after sending a REFER request for call transfer. The transfer target acknowledges receipt but hasn't completed the transfer yet.
Quando usar qual
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 202 (Accepted): Wait for a NOTIFY to learn the outcome of the referred action. If no NOTIFY arrives, check subscription state and network connectivity.