301
SIP
301 Moved Permanently
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.
Quand vous voyez ce code
When a user has permanently changed their SIP address. All future calls should be directed to the new URI.
Comment résoudre
Update your address book or routing tables to use the new Contact URI provided in the response.