SIP 199 Early Dialog Terminated vs 482 Loop Detected
SIP 199 (Early Dialog Terminated) is a 1xx Provisional response, while 482 (Loop Detected) is a 4xx Client Failure response. 199 indicates that a UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs. In contrast, 482 means that the server has detected a loop. The request was received with its own address in the Via header, indicating it has been forwarded back to itself.
描述
A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
何时出现
In forked call scenarios when one of the forked branches is cancelled because another branch was answered.
如何修复
No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully.
描述
The server has detected a loop. The request was received with its own address in the Via header, indicating it has been forwarded back to itself.
何时出现
When routing configuration causes a request to cycle between two or more proxies without reaching the callee.
如何修复
Review proxy routing tables and DNS records. Check for circular references in SIP routing. Fix the routing configuration to break the loop.
主要区别
199 is a 1xx Provisional response, while 482 is a 4xx Client Failure response.
SIP 199: A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
SIP 482: The server has detected a loop. The request was received with its own address in the Via header, indicating it has been forwarded back to itself.
You encounter 199 when in forked call scenarios when one of the forked branches is cancelled because another branch was answered.
You encounter 482 when when routing configuration causes a request to cycle between two or more proxies without reaching the callee.
何时使用哪个
For 199 (Early Dialog Terminated): No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully. For 482 (Loop Detected): Review proxy routing tables and DNS records. Check for circular references in SIP routing. Fix the routing configuration to break the loop.