I have been working on getting my multi-node BBS back online using some FOSSIL drivers and telnet instead of dial-up modems.

One large problem is the speed Windows NTVDM (DOS Console) gives to legacy 16-bit applications running inside of it. You can really tell the difference from running a pure DOS 6.22 install with a packet driver and FOSSIL -> Telnet software and running say Windows 2003 server with the software inside a DOS box, especially when drawing full screen ANSI.

So this is what I did, I found the best combination by running two Windows NT 4 Servers (inside ESXi), and then loading TelSrv on each. It’s odd that NT 4 handles DOS virtual machines (NTVDM) better then Windows 2000 and 2003. When the DOS software is setup correctly and tested, the NTVDM rarely used more then 20% spiking and around 3% idle.

Each ESXi virtual machine handles two nodes currently, for a total of four. Now the problem comes up how can I handle connections from the outside, coming into one port (23 Telnet) off the router and then choose which telnet server to redirect it to.

I built this small application in C# that will take in a telnet connection, and then based on the code at the moment, will direct it to a specific server based on some simple rules. Say, first connection and third to server one, and second and fourth to server two.

If you need more information on running it, you can check the source code that is available, as I cannot offer a compiled version. It would be of no use unless you changed the code anyway.

I suppose you could re-route any TCP socket connections using this, I know FTP will not work, as it uses two sockets.

Telnet Concentrator