SIP 202 Accepted vs 487 Request Terminated
SIP 202 (Accepted) is a 2xx Success response, while 487 (Request Terminated) is a 4xx Client Failure response. 202 indicates that the request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests. In contrast, 487 means that the request was terminated by a BYE or CANCEL. The original request was cancelled before it could be completed.
Mô tả
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.
Mô tả
The request was terminated by a BYE or CANCEL. The original request was cancelled before it could be completed.
Khi bạn thấy mã này
When the caller hangs up before the callee answers (CANCEL sent for pending INVITE). This is normal call abandonment.
Cách khắc phục
No fix needed — the caller intentionally terminated the request. This is normal behavior.
Sự khác biệt chính
202 is a 2xx Success response, while 487 is a 4xx Client Failure response.
SIP 202: The request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests.
SIP 487: The request was terminated by a BYE or CANCEL. The original request was cancelled before it could be completed.
You encounter 202 when after sending a REFER request for call transfer. The transfer target acknowledges receipt but hasn't completed the transfer yet.
You encounter 487 when when the caller hangs up before the callee answers (CANCEL sent for pending INVITE). This is normal call abandonment.
Khi nào dùng cái nào
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. For 487 (Request Terminated): No fix needed — the caller intentionally terminated the request. This is normal behavior.