SIP 301 Moved Permanently vs 502 Bad Gateway
SIP 301 (Moved Permanently) is a 3xx Redirection response, while 502 (Bad Gateway) is a 5xx Server 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, 502 means that the server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
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, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
When You See It
When a SIP proxy receives a malformed or invalid response from the next-hop server. Common in interop scenarios between different vendors.
How to Fix
Check the downstream server's health and configuration. Verify SIP message formatting between the two servers. Review network connectivity.
Key Differences
301 is a 3xx Redirection response, while 502 is a 5xx Server 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 502: The server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
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 502 when when a SIP proxy receives a malformed or invalid response from the next-hop server. Common in interop scenarios between different vendors.
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 502 (Bad Gateway): Check the downstream server's health and configuration. Verify SIP message formatting between the two servers. Review network connectivity.