SIP 202 Accepted vs 504 Server Time-out
SIP 202 (Accepted) is a 2xx Success response, while 504 (Server Time-out) is a 5xx Server 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, 504 means that the server did not receive a timely response from an external server it accessed while attempting to process the request. Different from 408 (client timeout).
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.
Descrição
The server did not receive a timely response from an external server it accessed while attempting to process the request. Different from 408 (client timeout).
Quando você o vê
When a proxy's request to a downstream server times out. The proxy itself is working, but the next hop is unresponsive.
Como corrigir
Check the downstream server's availability. Verify DNS resolution for the next-hop domain. Consider adjusting transaction timeout values.
Diferenças principais
202 is a 2xx Success response, while 504 is a 5xx Server Failure response.
SIP 202: The request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests.
SIP 504: The server did not receive a timely response from an external server it accessed while attempting to process the request. Different from 408 (client timeout).
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 504 when when a proxy's request to a downstream server times out. The proxy itself is working, but the next hop is unresponsive.
Quando usar qual
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 504 (Server Time-out): Check the downstream server's availability. Verify DNS resolution for the next-hop domain. Consider adjusting transaction timeout values.