TCP/UDP port mapping for full cone NAT
coturn TURN server project
Encrypted UDP based FTP with multicast
allows connecting to hosts behind firewalls and NAT
NetFlow iptables module for Linux kernel
A MAC address based user authentication system for campus-wide network
netflow collecting and processing tools
IPv4/IPv6 TCP Echo Server scaling to 100.000+ concurrent sessions
Mapping (aka stateless NAT) for IPv6