SIP 301 Moved Permanently vs 482 Loop Detected
SIP 301 (Moved Permanently) is a 3xx Redirection response, while 482 (Loop Detected) 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, 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 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 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
301 is a 3xx Redirection response, while 482 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 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.
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 482 when when routing configuration causes a request to cycle between two or more proxies without reaching the callee.
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 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.