It's the NAT / Firewall of the Vodia IO Router ! Basically, forwarding packets that arrive on a particular port to a specific local IP.
When a packet arrives at the router from outside, it checks if the external port (or port range) and optionally the remote IP match with those in one of the rules in the list; and if they do, then it forwards the packet to the corresponding local IP, and optionally the local port.
For example, if you want to host a web server on an internal machine with IP 192.168.1.2 and port 80, then you can set the external port to 80 and local IP to 192.168.1.2 on the TCP protocol.
