http://astrillrcpusdryujyzbsl7wsugvyfc5s6veyrpkojiqbrorgkfdxvid.onion/features/port-forwarding
Port forwarding, also called port mapping or port tunneling, is a method which is widely used to redirect computer signals or ports between local area network (LAN) computers and remote (Internet) computers. Layman definition of port forwarding is it's a feature you can use when you require access to an internet-enabled device or service from anywhere.