SIP

SIP 302 Moved Temporarily vs 415 Unsupported Media Type

SIP 302 (Moved Temporarily) is a 3xx Redirection response, while 415 (Unsupported Media Type) is a 4xx Client Failure response. 302 indicates that the callee has temporarily moved to a different address. The client should retry the request at the Contact address but continue using the original URI for future requests. 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 callee has temporarily moved to a different address. The client should retry the request at the Contact address but continue using the original URI for future requests.

When You See It

When a user is temporarily reachable at a different location, such as when traveling or using a different device.

How to Fix

Redirect the current call to the Contact URI provided, but keep the original URI for future requests.

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

1.

302 is a 3xx Redirection response, while 415 is a 4xx Client Failure response.

2.

SIP 302: The callee has temporarily moved to a different address. The client should retry the request at the Contact address but continue using the original URI for future requests.

3.

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.

4.

You encounter 302 when when a user is temporarily reachable at a different location, such as when traveling or using a different device.

5.

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 302 (Moved Temporarily): Redirect the current call to the Contact URI provided, but keep the original URI for future requests. 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.

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