SIP 182 Queued vs 204 No Notification
SIP 182 (Queued) is a 1xx Provisional response, while 204 (No Notification) is a 2xx Success 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, 204 means that the request was successful but the server has decided not to send a NOTIFY for this SUBSCRIBE request.
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 request was successful but the server has decided not to send a NOTIFY for this SUBSCRIBE request.
When You See It
When subscribing to event packages that may not generate immediate notifications, such as dialog or presence packages.
How to Fix
No fix needed. The subscription was accepted but there is no state change to notify about yet.
Key Differences
182 is a 1xx Provisional response, while 204 is a 2xx Success 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 204: The request was successful but the server has decided not to send a NOTIFY for this SUBSCRIBE request.
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 204 when when subscribing to event packages that may not generate immediate notifications, such as dialog or presence packages.
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 204 (No Notification): No fix needed. The subscription was accepted but there is no state change to notify about yet.