SIP 302 Moved Temporarily vs 488 Not Acceptable Here
SIP 302 (Moved Temporarily) is a 3xx Redirection response, while 488 (Not Acceptable Here) is a 4xx Client Failure response. 302 indicates that the callee has temporarily moved to a different address. The client should retry the request at the Contact address but continue using the original URI for future 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.
描述
The callee has temporarily moved to a different address. The client should retry the request at the Contact address but continue using the original URI for future requests.
何时出现
When a user is temporarily reachable at a different location, such as when traveling or using a different device.
如何修复
Redirect the current call to the Contact URI provided, but keep the original URI for future requests.
描述
The request was understood but the session description (SDP) is not acceptable. The response may contain a list of acceptable media parameters.
何时出现
When codec negotiation fails — the callee cannot handle any of the codecs offered in the SDP. Common in interop scenarios.
如何修复
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.
主要区别
302 is a 3xx Redirection response, while 488 is a 4xx Client Failure response.
SIP 302: The callee has temporarily moved to a different address. The client should retry the request at the Contact address but continue using the original URI for future 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 302 when when a user is temporarily reachable at a different location, such as when traveling or using a different device.
You encounter 488 when when codec negotiation fails — the callee cannot handle any of the codecs offered in the SDP. Common in interop scenarios.
何时使用哪个
For 302 (Moved Temporarily): Redirect the current call to the Contact URI provided, but keep the original URI for future requests. 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.