SIP 180 Ringing vs 380 Alternative Service
SIP 180 (Ringing) is a 1xx Provisional response, while 380 (Alternative Service) is a 3xx Redirection 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, 380 means that the call was not successful but alternative services are possible. The response body contains a description of alternative services.
Descrição
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.
Quando você o vê
During call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.
Como corrigir
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.
Descrição
The call was not successful but alternative services are possible. The response body contains a description of alternative services.
Quando você o vê
Rarely seen in practice. Indicates that the request cannot be fulfilled as-is but the user may be reached via an alternative method.
Como corrigir
Check the response body for alternative service descriptions and attempt to reach the user through those channels.
Diferenças principais
180 is a 1xx Provisional response, while 380 is a 3xx Redirection 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 380: The call was not successful but alternative services are possible. The response body contains a description of alternative services.
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 380 when rarely seen in practice. Indicates that the request cannot be fulfilled as-is but the user may be reached via an alternative method.
Quando usar qual
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 380 (Alternative Service): Check the response body for alternative service descriptions and attempt to reach the user through those channels.