You most likely got a router in your house, to enter it, you need to find your gateway. You can type run - cmd.exe and type "ipconfig" to see it.
After that, you just write your gateway in internet explorer/firefox or something like that, and you will get to login. You most likely got an default password like admin/blank.
If not, you can reset your router by pushing a tiny reset buttom at the router in your house.
After doing that, you can enter it, and open the ports you want, and you can let etc
all internet traffic through port 7171 goes to your 1st computer.
all internet traffic through port 7172 goes to your 2nd computer.
That way you can host your OT on your first computer using port 7171, and you can host another OT at the same time, at your 2nd computer using port 7172.