SIP 301 Moved Permanently vs 415 Unsupported Media Type
SIP 301 (Moved Permanently) is a 3xx Redirection response, while 415 (Unsupported Media Type) is a 4xx Client Failure response. 301 indicates that the user can no longer be found at the address in the Request-URI. The client should direct future requests to the new address in the Contact header. 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.
Description
The user can no longer be found at the address in the Request-URI. The client should direct future requests to the new address in the Contact header.
When You See It
When a user has permanently changed their SIP address. All future calls should be directed to the new URI.
How to Fix
Update your address book or routing tables to use the new Contact URI provided in the response.
Description
The server is refusing the request because the message body is in a format not supported by the server for the requested method.
When You See It
When the Content-Type of the request body is not supported. For INVITE, this often means an unsupported SDP format.
How to Fix
Check the Accept header in the response to see supported media types. Use a compatible Content-Type in your request.
Key Differences
301 is a 3xx Redirection response, while 415 is a 4xx Client Failure response.
SIP 301: The user can no longer be found at the address in the Request-URI. The client should direct future requests to the new address in the Contact header.
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 301 when when a user has permanently changed their SIP address. All future calls should be directed to the new URI.
You encounter 415 when when the Content-Type of the request body is not supported. For INVITE, this often means an unsupported SDP format.
When to Use Which
For 301 (Moved Permanently): Update your address book or routing tables to use the new Contact URI provided in the response. 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.