SIP 182 Queued vs 421 Extension Required
SIP 182 (Queued) is a 1xx Provisional response, while 421 (Extension Required) 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, 421 means that the UAS needs a particular extension to process the request but the extension is not listed in the Supported header.
설명
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.
이 코드를 보게 되는 경우
In call center or queuing scenarios where the callee is busy but the system holds the call in a queue.
해결 방법
Wait for the call to be dequeued. If queuing is not desired, configure the server to reject calls instead of queuing them.
설명
The UAS needs a particular extension to process the request but the extension is not listed in the Supported header.
이 코드를 보게 되는 경우
When the server requires a specific SIP extension that the client did not indicate support for.
해결 방법
Add the required extension to the Supported header and ensure your UA implements it. Check the response for which extension is needed.
주요 차이점
182 is a 1xx Provisional response, while 421 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 421: The UAS needs a particular extension to process the request but the extension is not listed in the Supported header.
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 421 when when the server requires a specific SIP extension that the client did not indicate support for.
언제 어떤 것을 사용할지
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 421 (Extension Required): Add the required extension to the Supported header and ensure your UA implements it. Check the response for which extension is needed.