SIP 182 Queued vs 430 Flow Failed
SIP 182 (Queued) is a 1xx Provisional response, while 430 (Flow 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, 430 means that the specific flow to a user agent has failed but other flows may succeed. Used with SIP outbound (RFC 5626).
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 specific flow to a user agent has failed but other flows may succeed. Used with SIP outbound (RFC 5626).
When You See It
When using SIP outbound connections and the specific TCP/TLS connection (flow) to the UA has been lost.
How to Fix
The proxy should attempt delivery via other registered flows. The UA should re-register to establish a new flow.
Key Differences
182 is a 1xx Provisional response, while 430 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 430: The specific flow to a user agent has failed but other flows may succeed. Used with SIP outbound (RFC 5626).
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 430 when when using SIP outbound connections and the specific TCP/TLS connection (flow) to the UA has been lost.
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 430 (Flow Failed): The proxy should attempt delivery via other registered flows. The UA should re-register to establish a new flow.