SIP 182 Queued vs 488 Not Acceptable Here
SIP 182 (Queued) is a 1xx Provisional response, while 488 (Not Acceptable Here) is a 4xx Client Failure response. 182 indicates that the called party is temporarily unavailable but the server has decided to queue the call rather than reject it. The call will be attempted when the callee becomes available. 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.
Descrição
The called party is temporarily unavailable but the server has decided to queue the call rather than reject it. The call will be attempted when the callee becomes available.
Quando você o vê
In call center or queuing scenarios where the callee is busy but the system holds the call in a queue.
Como corrigir
Wait for the call to be dequeued. If queuing is not desired, configure the server to reject calls instead of queuing them.
Descrição
The request was understood but the session description (SDP) is not acceptable. The response may contain a list of acceptable media parameters.
Quando você o vê
When codec negotiation fails — the callee cannot handle any of the codecs offered in the SDP. Common in interop scenarios.
Como corrigir
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.
Diferenças principais
182 is a 1xx Provisional response, while 488 is a 4xx Client Failure response.
SIP 182: The called party is temporarily unavailable but the server has decided to queue the call rather than reject it. The call will be attempted when the callee becomes available.
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 182 when in call center or queuing scenarios where the callee is busy but the system holds the call in a queue.
You encounter 488 when when codec negotiation fails — the callee cannot handle any of the codecs offered in the SDP. Common in interop scenarios.
Quando usar qual
For 182 (Queued): Wait for the call to be dequeued. If queuing is not desired, configure the server to reject calls instead of queuing them. 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.