UTT-901 User Manual13NAT Enable NAT.4.4 VOIP configuration4.4.1 SIP configurationUser can configure specific parameter of SIP signaling protocol on thispage.Configuration Explanation:SIP[Registered]Configurationshow SIP register state; if register successfully, therewill show Registered in the square bracket, otherwiseshow Unregistered.Register ServerAddrConfigure SIP register server IP address.Register ServerPortConfigure SIP register server signal port.RegisterUsernameConfigure SIP register account(usually it is the samewith the port number that configured, some special