SIP 202 Accepted vs 488 Not Acceptable Here
SIP 202 (Accepted) is a 2xx Success response, while 488 (Not Acceptable Here) 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, 488 means that the request was understood but the session description (SDP) is not acceptable. The response may contain a list of acceptable media parameters.
설명
The request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests.
이 코드를 보게 되는 경우
After sending a REFER request for call transfer. The transfer target acknowledges receipt but hasn't completed the transfer yet.
해결 방법
Wait for a NOTIFY to learn the outcome of the referred action. If no NOTIFY arrives, check subscription state and network connectivity.
설명
The request was understood but the session description (SDP) is not acceptable. The response may contain a list of acceptable media parameters.
이 코드를 보게 되는 경우
When codec negotiation fails — the callee cannot handle any of the codecs offered in the SDP. Common in interop scenarios.
해결 방법
Check the Warning header or SDP in the response for acceptable parameters. Add compatible codecs (e.g., G.711 as a fallback) to your offer.
주요 차이점
202 is a 2xx Success response, while 488 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 488: The request was understood but the session description (SDP) is not acceptable. The response may contain a list of acceptable media parameters.
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 488 when when codec negotiation fails — the callee cannot handle any of the codecs offered in the SDP. Common in interop scenarios.
언제 어떤 것을 사용할지
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 488 (Not Acceptable Here): Check the Warning header or SDP in the response for acceptable parameters. Add compatible codecs (e.g., G.711 as a fallback) to your offer.