TCPView - TCPView is a Windows program that will show you detailed listings of all TCP and UDP endpoints on...
PortMapper - Do you need to map a specific TCP or UDP port on your machine to another port on another machine?
CurrPorts - CurrPorts displays the list of all currently opened TCP/IP and UDP ports on your local computer.
netcat - Netcat is a featured networking utility which reads and writes data across network connections...
TCP Optimizer - SpeedGuide.net - The Broadband Guide. Cable modems, DSL, Wireless, Network security. Free speed tweaks and TCP/IP tools for optimizing system performance.
Komodia Relay - Free open source tool to perform TCP based session relay