I also put the fixed IP address of LMCE into the DMZ on the router.
In yet another attempt last night to get it to work I changed the IP address from a fixed address to obtain from the router DHCP and allong with putting this address into the DMZ sipgate showed the astersik as being online.
Good you might think.
But now I am unable to place or receive calls through sipgate.
I suppose the next step will be to try the FWD again to see if that will work.