Closed Ports

I'm trying to configure this program, Fantasy Grounds, and thought it manages to execute, I can't neither connect to another host or host myself. Accordingly, it seems the problem is that my port 1802 is closed. At first, I thought the firewall was the problem, yet tweaking it didn't help a bit. Apparently, it could be the router the one messing up my connections and ports.

Is there some way to configure the router, or somehow open that port?

portforwarding, you will need to forward 1802, 3389, and 23 for this to work