SIP 100 Trying vs 415 Unsupported Media Type
SIP 100 (Trying) is a 1xx Provisional response, while 415 (Unsupported Media Type) 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, 415 means that the server is refusing the request because the message body is in a format not supported by the server for the requested method.
Mô tả
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.
Khi bạn thấy mã này
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.
Cách khắc phục
No fix needed — this is normal call setup behavior. If stuck on 100 Trying for too long, check network connectivity and proxy configuration.
Mô tả
The server is refusing the request because the message body is in a format not supported by the server for the requested method.
Khi bạn thấy mã này
When the Content-Type of the request body is not supported. For INVITE, this often means an unsupported SDP format.
Cách khắc phục
Check the Accept header in the response to see supported media types. Use a compatible Content-Type in your request.
Sự khác biệt chính
100 is a 1xx Provisional response, while 415 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 415: The server is refusing the request because the message body is in a format not supported by the server for the requested method.
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 415 when when the Content-Type of the request body is not supported. For INVITE, this often means an unsupported SDP format.
Khi nào dùng cái nào
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 415 (Unsupported Media Type): Check the Accept header in the response to see supported media types. Use a compatible Content-Type in your request.