SIP 181 Call Is Being Forwarded vs 380 Alternative Service
SIP 181 (Call Is Being Forwarded) is a 1xx Provisional response, while 380 (Alternative Service) is a 3xx Redirection response. 181 indicates that a proxy server may send this to indicate that the call is being forwarded to a different set of destinations. In contrast, 380 means that the call was not successful but alternative services are possible. The response body contains a description of alternative services.
Description
A proxy server may send this to indicate that the call is being forwarded to a different set of destinations.
Quand vous le voyez
When the callee has call forwarding enabled and the request is being redirected to another number or device.
Comment résoudre
No action needed. The call is being redirected. If forwarding is unintended, the callee should update their forwarding settings.
Description
The call was not successful but alternative services are possible. The response body contains a description of alternative services.
Quand vous le voyez
Rarely seen in practice. Indicates that the request cannot be fulfilled as-is but the user may be reached via an alternative method.
Comment résoudre
Check the response body for alternative service descriptions and attempt to reach the user through those channels.
Différences clés
181 is a 1xx Provisional response, while 380 is a 3xx Redirection response.
SIP 181: A proxy server may send this to indicate that the call is being forwarded to a different set of destinations.
SIP 380: The call was not successful but alternative services are possible. The response body contains a description of alternative services.
You encounter 181 when when the callee has call forwarding enabled and the request is being redirected to another number or device.
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.
Quand utiliser lequel
For 181 (Call Is Being Forwarded): No action needed. The call is being redirected. If forwarding is unintended, the callee should update their forwarding settings. For 380 (Alternative Service): Check the response body for alternative service descriptions and attempt to reach the user through those channels.