When Xlite is in the same network with CME the registration works fine. When I try to connect Xlite outside the network I receive 408 - Request Timeout. The CME is behind NAT so I configure port forward - public 5060 to CME 5060 port, but the same result. With the same port forward configurations and non-Cisco gateway the registration works fine.
Are there any other configurations for CME in order to register Xlite from outside the network?