:param protocol: IP protocol (Default value = 0)
:param twice_nat: 1 if translate external host address and port
:param out2in_only: if 1 rule is matching only out2in direction
:param protocol: IP protocol (Default value = 0)
:param twice_nat: 1 if translate external host address and port
:param out2in_only: if 1 rule is matching only out2in direction