The main source of slavery in this part of the world in the Middle Ages was indebtedness. In China, impoverished peasants frequently sold members of their own families into slavery, and throughout the entire medieval period criminals or members of their families became slaves of the state.
Nonetheless, NAT can introduce complications in communication between hosts.     * NAT(Network Address Translation) is most commonly used by broadband routers. NAT allows the router to assign non-publically routable IP addresses to the computers on the network.
NAT options on domestic routers often come configured as strict. What does this mean? What do moderate or open do? Port-forwarding/DMZ access works properly on strict so why bother with the other two? A look through the router suggests this affects the firewall.