SIP 181 Call Is Being Forwarded vs 505 Version Not Supported
SIP 181 (Call Is Being Forwarded) is a 1xx Provisional response, while 505 (Version Not Supported) is a 5xx Server Failure 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, 505 means that the server does not support the SIP protocol version that was used in the request. Currently only SIP/2.0 is standardized.
Descrição
A proxy server may send this to indicate that the call is being forwarded to a different set of destinations.
Quando você o vê
When the callee has call forwarding enabled and the request is being redirected to another number or device.
Como corrigir
No action needed. The call is being redirected. If forwarding is unintended, the callee should update their forwarding settings.
Descrição
The server does not support the SIP protocol version that was used in the request. Currently only SIP/2.0 is standardized.
Quando você o vê
Extremely rare. Would occur if a client sends a request with a SIP version other than 2.0.
Como corrigir
Ensure your UA uses SIP/2.0 in the request line. This is the only standardized version.
Diferenças principais
181 is a 1xx Provisional response, while 505 is a 5xx Server Failure response.
SIP 181: A proxy server may send this to indicate that the call is being forwarded to a different set of destinations.
SIP 505: The server does not support the SIP protocol version that was used in the request. Currently only SIP/2.0 is standardized.
You encounter 181 when when the callee has call forwarding enabled and the request is being redirected to another number or device.
You encounter 505 when extremely rare. Would occur if a client sends a request with a SIP version other than 2.0.
Quando usar qual
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 505 (Version Not Supported): Ensure your UA uses SIP/2.0 in the request line. This is the only standardized version.