SIP 100 Trying vs 412 Conditional Request Failed
SIP 100 (Trying) is a 1xx Provisional response, while 412 (Conditional Request Failed) is a 4xx Client Failure response. 100 indicates that the request has been received by the next-hop server and an unspecified action is being taken to process it. The UAC should expect additional responses. In contrast, 412 means that the precondition given in the request was not met. Used with SIP event state publication (RFC 3903).
説明
The request has been received by the next-hop server and an unspecified action is being taken to process it. The UAC should expect additional responses.
このコードが表示される場合
Immediately after sending an INVITE. The proxy has received the call and is searching for the callee. This is the SIP equivalent of a dial tone.
解決方法
No fix needed — this is normal call setup behavior. If stuck on 100 Trying for too long, check network connectivity and proxy configuration.
説明
The precondition given in the request was not met. Used with SIP event state publication (RFC 3903).
このコードが表示される場合
When a PUBLISH request includes an If-Match header with an entity tag that does not match the current state on the server.
解決方法
Refresh the entity tag by performing a new PUBLISH without If-Match, then use the returned SIP-ETag for subsequent updates.
主な違い
100 is a 1xx Provisional response, while 412 is a 4xx Client Failure response.
SIP 100: The request has been received by the next-hop server and an unspecified action is being taken to process it. The UAC should expect additional responses.
SIP 412: The precondition given in the request was not met. Used with SIP event state publication (RFC 3903).
You encounter 100 when immediately after sending an INVITE. The proxy has received the call and is searching for the callee. This is the SIP equivalent of a dial tone.
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.
どちらをいつ使うか
For 100 (Trying): No fix needed — this is normal call setup behavior. If stuck on 100 Trying for too long, check network connectivity and proxy configuration. 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.