Thought I would take a minute to post some info based on some MP tests I tried this evening with Hundane, GIJoe and a few others.
We had about 7 of us this evening trying to join and only Hundane and myself could get into the game through our default setups. GIJoe got in by manually bypassing his router, but that's not the ideal solution. I did get a chance to speak with Scott and GameRanger and he offered some useful tips.
* When you are in GameRanger and it brings up the warning for "Port-Restricted Cone NAT Router" there is a Learn More button. It brings up a window with a link that will attempt to get you into your routers configuration page. Here's what it says;
Port-Restricted Cone NAT Router
Your internet connection is behind a Port-Restricted Cone NAT Router that may prevent you from connecting to some players in peer-peer games.
You will still be able to connect with the majority of players, but not with those who have Symmetric NAT Routers (which are not that common, fortunately). One advantage of fixing this problem is that the "Preparing Connection" window will complete much faster.
If you do want to solve this problem, it will involve you configuring your router. Most routers are configured through a web page built into them. You may be able to reach yours here.
Many recent routers support a feature called Universal Plug and Play (UPnP). This feature will allow GameRanger to do most of the configuration required. You will need to enable it to allow GameRanger to make changes. Not all routers support UPnP correctly, however, so that may not be enough.
The alternative is to manually configure your router to do port-forwarding for UDP port 16000. Ask your ISP (Internet Service Provider) or refer to your router's instruction manual for assistance here.
Port-forwarding tells the router to send the game communication data to your computer. The port-forwarding configuration page will ask you for a public port and a private port. Set both of those to 16000. In some cases, instead of asking for a public port, it will ask for a port range (eg. Start Port, End Port). Set the Start and End to 16000. It will also ask you for the IP address of your computer that the data should be sent to. It may call this the LAN IP, Local IP, or Private IP. This should be set to 192.168.1.100. If it asks you for the protocol or type, set it to UDP.
Unfortunately, it is not possible to offer step-by-step instructions here as every router is different.
If you are at work on a company network or at a university, you may not be able to fix the problem yourself. Instead you may have to ask the network administrator to how to port-forward UDP port 16000 to your computer.
* if you see a user who's name is italicized, that means that GameRanger has determined it cannot connect you to that player. Sometimes it still works, but it indicates a potential problem. (the tests we ran tonight should have been with me and one user at a time).
And for those asking "what port is used", Supreme Ruler 2020 uses DirectX's DirectPlay networking code which uses multiple ports. If anyone can find details on the ports used by Microsft for DirectPlay, we can test some of that to see if we can do more targeted port forwarding.
If you catch me online, I can usually take the 5 mins to run a quick test connection.