If your local IP Adress is "192.168.1.0-255" Then your router prolly got
"192.168.1.1" but if you got "182.168.0.0-255" Then your router prolly got "192.168.0.1"
Go ahead and write that into your webbrowser and you should get to a page where u can log on to your router, login info is usualy admin/blank or admin/1234 or soemthing like that it could be blank/blank to
When u are fianlly logged in, finde "portforward/forwarding/firewall" or whatever it could be
and open a 7171 port for both TCP and UDP.
If you dont know what local IP you got, open CMD and type "ipconfig"
Hope i could help