SIP 181 Call Is Being Forwarded vs 400 Bad Request
SIP 181 (Call Is Being Forwarded) is a 1xx Provisional response, while 400 (Bad Request) is a 4xx Client 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, 400 means that the request could not be understood due to malformed syntax. The client should not repeat the request without modifications.
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 request could not be understood due to malformed syntax. The client should not repeat the request without modifications.
Quando você o vê
When the SIP message has syntax errors, missing required headers, or invalid header values.
Como corrigir
Review the SIP message for syntax errors. Check required headers (To, From, Call-ID, CSeq, Via, Max-Forwards) and ensure proper formatting.
Diferenças principais
181 is a 1xx Provisional response, while 400 is a 4xx Client 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 400: The request could not be understood due to malformed syntax. The client should not repeat the request without modifications.
You encounter 181 when when the callee has call forwarding enabled and the request is being redirected to another number or device.
You encounter 400 when when the SIP message has syntax errors, missing required headers, or invalid header values.
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 400 (Bad Request): Review the SIP message for syntax errors. Check required headers (To, From, Call-ID, CSeq, Via, Max-Forwards) and ensure proper formatting.