PFConfig

PortForward’s PFConfig Software lets you forward ports on any router for any program.

AUTAPF

Reliable TCP and UDP port forwarding for Windows.

miniupnp project homepage : a lightweight upnp client and daemon

Portfwd, Port Forwarding Daemon, stands for port forwarding daemon.

Router is the best way to view & edit .GPX, .TCX, .KML, .LOC, Garmin (.FIT), and Pioneer (.DB) GPS route files on your Mac

socat is a relay for bidirectional data transfer between two independent data channels.

tcpdump is a common packet analyzer that runs under the command line.