DD-WRT:Network Address Translation

NAPT (network address and port translation) is a necessary because of to few public internet (IPv4) addresses or for other reasons.

NAPT is commonly referred to as NAT (Network address translation).

The NAPT is normally done by a router or firewall with NAPT functionalty - e.g. DD-WRT software!

Note: Private ip addresses must be (source) translated (NATted, tcp, udp: PAT) to a public (=non-private) ip address (tcp: socket) before its payload can be send into the (public) internet.