SIP 202 Accepted vs 412 Conditional Request Failed
SIP 202 (Accepted) is a 2xx Success response, while 412 (Conditional Request Failed) 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, 412 means that the precondition given in the request was not met. Used with SIP event state publication (RFC 3903).
説明
The request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests.
このコードが表示される場合
After sending a REFER request for call transfer. The transfer target acknowledges receipt but hasn't completed the transfer yet.
解決方法
Wait for a NOTIFY to learn the outcome of the referred action. If no NOTIFY arrives, check subscription state and network connectivity.
説明
The precondition given in the request was not met. Used with SIP event state publication (RFC 3903).
このコードが表示される場合
When a PUBLISH request includes an If-Match header with an entity tag that does not match the current state on the server.
解決方法
Refresh the entity tag by performing a new PUBLISH without If-Match, then use the returned SIP-ETag for subsequent updates.
主な違い
202 is a 2xx Success response, while 412 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 412: The precondition given in the request was not met. Used with SIP event state publication (RFC 3903).
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 412 when when a PUBLISH request includes an If-Match header with an entity tag that does not match the current state on the server.
どちらをいつ使うか
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 412 (Conditional Request Failed): Refresh the entity tag by performing a new PUBLISH without If-Match, then use the returned SIP-ETag for subsequent updates.