SIP 180 Ringing vs 408 Request Timeout
SIP 180 (Ringing) is a 1xx Provisional response, while 408 (Request Timeout) is a 4xx Client Failure response. 180 indicates that the UA receiving the INVITE is trying to alert the user. This response is used to initiate local ringback tone at the caller's end. In contrast, 408 means that the server could not produce a response within a suitable time. The client may repeat the request without modifications at any later time.
Description
The UA receiving the INVITE is trying to alert the user. This response is used to initiate local ringback tone at the caller's end.
When You See It
During call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.
How to Fix
No fix needed — the callee's device is ringing. If the call never connects after ringing, check the callee's device or call forwarding settings.
Description
The server could not produce a response within a suitable time. The client may repeat the request without modifications at any later time.
When You See It
When the callee does not respond within the configured timeout (e.g., phone rings but is never answered, or the endpoint is unreachable).
How to Fix
Check if the callee's device is powered on and registered. Verify network connectivity. Consider adjusting the server's transaction timeout value.
Key Differences
180 is a 1xx Provisional response, while 408 is a 4xx Client Failure response.
SIP 180: The UA receiving the INVITE is trying to alert the user. This response is used to initiate local ringback tone at the caller's end.
SIP 408: The server could not produce a response within a suitable time. The client may repeat the request without modifications at any later time.
You encounter 180 when during call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.
You encounter 408 when when the callee does not respond within the configured timeout (e.g., phone rings but is never answered, or the endpoint is unreachable).
When to Use Which
For 180 (Ringing): No fix needed — the callee's device is ringing. If the call never connects after ringing, check the callee's device or call forwarding settings. For 408 (Request Timeout): Check if the callee's device is powered on and registered. Verify network connectivity. Consider adjusting the server's transaction timeout value.