SIP 301 Moved Permanently vs 305 Use Proxy
Both SIP 301 (Moved Permanently) and 305 (Use Proxy) belong to the 3xx Redirection category. 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. Meanwhile, 305 means that the requested resource must be accessed through the proxy given by the Contact header field.
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 requested resource must be accessed through the proxy given by the Contact header field.
When You See It
When the request must be routed through a specific outbound proxy server.
How to Fix
Resend the request through the proxy specified in the Contact header of this response.
Key Differences
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 305: The requested resource must be accessed through the proxy given by the Contact header field.
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 305 when when the request must be routed through a specific outbound proxy server.
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 305 (Use Proxy): Resend the request through the proxy specified in the Contact header of this response.