SIP 182 Queued vs 503 Service Unavailable
SIP 182 (Queued) is a 1xx Provisional response, while 503 (Service Unavailable) is a 5xx Server 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, 503 means that the server is temporarily unable to process the request due to overloading or maintenance. The client should retry after the time indicated in the Retry-After header.
Описание
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.
Когда вы это видите
In call center or queuing scenarios where the callee is busy but the system holds the call in a queue.
Как исправить
Wait for the call to be dequeued. If queuing is not desired, configure the server to reject calls instead of queuing them.
Описание
The server is temporarily unable to process the request due to overloading or maintenance. The client should retry after the time indicated in the Retry-After header.
Когда вы это видите
During server overload, maintenance windows, or when the server is rate-limiting requests. Common during traffic spikes.
Как исправить
Wait for the time specified in the Retry-After header. If persistent, check server capacity and consider load balancing across multiple SIP proxies.
Ключевые различия
182 is a 1xx Provisional response, while 503 is a 5xx Server 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 503: The server is temporarily unable to process the request due to overloading or maintenance. The client should retry after the time indicated in the Retry-After 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 503 when during server overload, maintenance windows, or when the server is rate-limiting requests. Common during traffic spikes.
Когда что использовать
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 503 (Service Unavailable): Wait for the time specified in the Retry-After header. If persistent, check server capacity and consider load balancing across multiple SIP proxies.