How are peers establishing a direct connection to another clients computer without port-forwarding?
Because I believe you have to open the port to allow connections, and if a port isn't open they can't establish a connection, which means they must use a relay server of some sort. But the only problem then it is no longer a P2P connection.
Are they using an exploit of some sort to get around the firewall?
Could someone explain this to me like I'm 5. (I know this is isn't /r/ELI5 sub-reddit but this is really confusing for me to understand.)
