SIP 181 Call Is Being Forwarded vs 412 Conditional Request Failed
SIP 181 (Call Is Being Forwarded) is a 1xx Provisional response, while 412 (Conditional Request Failed) 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, 412 means that the precondition given in the request was not met. Used with SIP event state publication (RFC 3903).
描述
A proxy server may send this to indicate that the call is being forwarded to a different set of destinations.
何时出现
When the callee has call forwarding enabled and the request is being redirected to another number or device.
如何修复
No action needed. The call is being redirected. If forwarding is unintended, the callee should update their forwarding settings.
描述
The precondition given in the request was not met. Used with SIP event state publication (RFC 3903).
何时出现
When a PUBLISH request includes an If-Match header with an entity tag that does not match the current state on the server.
如何修复
Refresh the entity tag by performing a new PUBLISH without If-Match, then use the returned SIP-ETag for subsequent updates.
主要区别
181 is a 1xx Provisional response, while 412 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 412: The precondition given in the request was not met. Used with SIP event state publication (RFC 3903).
You encounter 181 when when the callee has call forwarding enabled and the request is being redirected to another number or device.
You encounter 412 when when a PUBLISH request includes an If-Match header with an entity tag that does not match the current state on the server.
何时使用哪个
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 412 (Conditional Request Failed): Refresh the entity tag by performing a new PUBLISH without If-Match, then use the returned SIP-ETag for subsequent updates.