SIP 182 Queued vs 487 Request Terminated
SIP 182 (Queued) is a 1xx Provisional response, while 487 (Request Terminated) 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, 487 means that the request was terminated by a BYE or CANCEL. The original request was cancelled before it could be completed.
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 terminated by a BYE or CANCEL. The original request was cancelled before it could be completed.
Quando você o vê
When the caller hangs up before the callee answers (CANCEL sent for pending INVITE). This is normal call abandonment.
Como corrigir
No fix needed — the caller intentionally terminated the request. This is normal behavior.
Diferenças principais
182 is a 1xx Provisional response, while 487 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 487: The request was terminated by a BYE or CANCEL. The original request was cancelled before it could be completed.
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 487 when when the caller hangs up before the callee answers (CANCEL sent for pending INVITE). This is normal call abandonment.
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 487 (Request Terminated): No fix needed — the caller intentionally terminated the request. This is normal behavior.