SIP 180 Ringing vs 504 Server Time-out
SIP 180 (Ringing) is a 1xx Provisional response, while 504 (Server Time-out) is a 5xx Server 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, 504 means that the server did not receive a timely response from an external server it accessed while attempting to process the request. Different from 408 (client timeout).
Beschreibung
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.
Wann Sie es sehen
During call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.
Wie man es behebt
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.
Beschreibung
The server did not receive a timely response from an external server it accessed while attempting to process the request. Different from 408 (client timeout).
Wann Sie es sehen
When a proxy's request to a downstream server times out. The proxy itself is working, but the next hop is unresponsive.
Wie man es behebt
Check the downstream server's availability. Verify DNS resolution for the next-hop domain. Consider adjusting transaction timeout values.
Wesentliche Unterschiede
180 is a 1xx Provisional response, while 504 is a 5xx Server 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 504: The server did not receive a timely response from an external server it accessed while attempting to process the request. Different from 408 (client timeout).
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 504 when when a proxy's request to a downstream server times out. The proxy itself is working, but the next hop is unresponsive.
Wann welchen verwenden
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 504 (Server Time-out): Check the downstream server's availability. Verify DNS resolution for the next-hop domain. Consider adjusting transaction timeout values.