SIP

SIP 302 Moved Temporarily vs 482 Loop Detected

SIP 302 (Moved Temporarily) is a 3xx Redirection response, while 482 (Loop Detected) 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, 482 means that the server has detected a loop. The request was received with its own address in the Via header, indicating it has been forwarded back to itself.

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 has detected a loop. The request was received with its own address in the Via header, indicating it has been forwarded back to itself.

When You See It

When routing configuration causes a request to cycle between two or more proxies without reaching the callee.

How to Fix

Review proxy routing tables and DNS records. Check for circular references in SIP routing. Fix the routing configuration to break the loop.

Key Differences

1.

302 is a 3xx Redirection response, while 482 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 482: The server has detected a loop. The request was received with its own address in the Via header, indicating it has been forwarded back to itself.

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 482 when when routing configuration causes a request to cycle between two or more proxies without reaching the callee.

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 482 (Loop Detected): Review proxy routing tables and DNS records. Check for circular references in SIP routing. Fix the routing configuration to break the loop.

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