After giving this some thought, I've decided to shelve the RailPro Internet Trainer and CGNAT Proxy Server project to work around the CGNAT issue. There are a few reasons for this, namely people must be happy they can not connect to and download from Ring Engineering as no "can not connect" people came forward to help test it; either that or TR has gotten everyone scared of me with the things he has said.
The other reasons are to be able to run the proxy 24/7 instead of a few hours per day I'd have to build a low power server (electricity is expensive) and I'm not willing to spend money on that if it won't get used; and as Rings server is only IP address based for connections instead of what it should be only one person can use the proxy at a time (as the proxy would only have a single IP address itself). I'd have to dream up some sort of "log in system" (which might mean a completely different proxy mechanism) so not more than one user could use it at the same time, which is likely a much bigger headache to write than it sounds.
Although I invested quite a bit of time writing the trainer software and working out a rough but usable proxy it was fun to do it and see that it worked, so it does leave me sorry not to continue with it but the low power server and the "log in system" are not something I see as surmountable at this time.
Hopefully for everyone what should have been for TR a "10 minute" job to fix the RP software and server will get fixed sometime this year!
- Tim