SIP 182 Queued vs 412 Conditional Request Failed
SIP 182 (Queued) is a 1xx Provisional response, while 412 (Conditional Request Failed) 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, 412 means that the precondition given in the request was not met. Used with SIP event state publication (RFC 3903).
Description
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.
When You See It
In call center or queuing scenarios where the callee is busy but the system holds the call in a queue.
How to Fix
Wait for the call to be dequeued. If queuing is not desired, configure the server to reject calls instead of queuing them.
Description
The precondition given in the request was not met. Used with SIP event state publication (RFC 3903).
When You See It
When a PUBLISH request includes an If-Match header with an entity tag that does not match the current state on the server.
How to Fix
Refresh the entity tag by performing a new PUBLISH without If-Match, then use the returned SIP-ETag for subsequent updates.
Key Differences
182 is a 1xx Provisional response, while 412 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 412: The precondition given in the request was not met. Used with SIP event state publication (RFC 3903).
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 412 when when a PUBLISH request includes an If-Match header with an entity tag that does not match the current state on the server.
When to Use Which
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 412 (Conditional Request Failed): Refresh the entity tag by performing a new PUBLISH without If-Match, then use the returned SIP-ETag for subsequent updates.