My provider only want to give me one public IP Address and I do have some incoming traffic (Netscaler/Citrix on 443, a Minecraft Server and other).,Fot those reasons,  definig the WII as a “DMZ Host” or a portfowarding tcp/udp 1-65535… does not realy fit for me

I want to still keep the rest of the internal network reasonably safe
From various posts on the Internet I learned some ports

TCP 28910 29900 29901 29920 6667 12400 80 443

The NAT Type classification system boils down to a port-assignment policy.

Open NAT means that either the port-assignment policy is minimal or the device has a fully compliant version of UPnP (Universal Plug and Play) enabled by default. Moderate NAT means that the port-assignment policy is minimal, but the device is filtering addresses or ports. Strict NAT means the port-assignment policy is aggressive. How to make router/firewall to be open kind?

To make the firewall/router from strict to open, actually Microsoft′s devices looking for three UDP ports to be properly routed. If you can add following ports to the NAT rules on the router, it will be considered open: UDP port 5060; UDP port 5061; UDP port 3074;