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.
The Network Address Translation (NAT) performed by the router allows multiple computers (machines) connected to the LAN behind the router to communicate with the external Internet. The most common use for NAT routers is serving as an interface between the global public WAN Internet and a private non-public LAN: