FlySource is a peer-to-peer application. To use the sharing features, you need to open your firewall and configure port forwarding. In FlySource, open the Edit Preferences file menu. Notice the "Share Port" number? The default value is 8001. This is the port you need to forward to the computer that is running FlySource.

Because of the large number of routers on the market, Kevin is unable to help everyone configure their networks to work with FlySource. Your best hope for help is this website. NOTE!! I DO NOT RECOMMEND YOU BUY THE PROGRAM LISTED ON THAT WEBSITE! But, there is FREE information listed on the website that you can use. Look for your model of router and do your best to try and figure it out. If you are absolutely stuck and don't have someone who can drop by your place to help you out, you can try emailing Kevin at kumbach@gmail.com. He'll do his best to help out.