SIP 182 Queued vs 481 Call/Transaction Does Not Exist
SIP 182 (Queued) is a 1xx Provisional response, while 481 (Call/Transaction Does Not Exist) 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, 481 means that the UAS received a request that does not match any existing dialog or transaction. The call state may have been lost.
Mô tả
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.
Khi bạn thấy mã này
In call center or queuing scenarios where the callee is busy but the system holds the call in a queue.
Cách khắc phục
Wait for the call to be dequeued. If queuing is not desired, configure the server to reject calls instead of queuing them.
Mô tả
The UAS received a request that does not match any existing dialog or transaction. The call state may have been lost.
Khi bạn thấy mã này
When sending a BYE, re-INVITE, or UPDATE for a call that the server has no record of. Common after server restarts.
Cách khắc phục
The dialog has been lost. Terminate the local call state. For re-INVITE failures, re-establish the call from scratch.
Sự khác biệt chính
182 is a 1xx Provisional response, while 481 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 481: The UAS received a request that does not match any existing dialog or transaction. The call state may have been lost.
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 481 when when sending a BYE, re-INVITE, or UPDATE for a call that the server has no record of. Common after server restarts.
Khi nào dùng cái nào
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 481 (Call/Transaction Does Not Exist): The dialog has been lost. Terminate the local call state. For re-INVITE failures, re-establish the call from scratch.