SIP
202 Accepted
The request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests.
Khi bạn thấy mã này
After sending a REFER request for call transfer. The transfer target acknowledges receipt but hasn't completed the transfer yet.
Cách khắc phục
Wait for a NOTIFY to learn the outcome of the referred action. If no NOTIFY arrives, check subscription state and network connectivity.