Port Ping is a .NET Framework 3.5 Based utility application to test the text based communication protocol with any other application. It can connection to any TCP/IP port, using two parameters - Port Number and Address. Once it is connected it can be manually disconnected whenever it wishes to be.
HW Virtual Serial Port allows creating virual serial port drivers.
Multifunctional serial port monitoring application.
A software which displays the status of IP devices on your network.
Free, unrestricted Virtual Serial Port driver for any TCP/IP devices.
Reverse port forwarding can be referred to as reverse tunnel.