Serial Port Mapper allows you to map any serial ports to any other serial ports. For example you install additional serial port expansion card to computer as COM7 serial port but your favorite software can work with COM1...COM4 ports only. To resolve this problem you can use Serial Port Mapper to map new COM7 port either to COM1 or to COM2...COM4. Now your software can open COM1 port (or COM2...COM4) but actually work with new COM7 port. Configuration via command line interface is available as well.
Replace serial cables with ethernet network
Serial Port Redirector 2.7.6
Bridge serial app and a TCP/IP network
Network Serial Port Kit 5.8.11
Connects serial devices over TCP/IP network
VSP adds virtual serial port(s) to OS.
Virtual Serial Port Kit 5.5.5
Creates pairs of virtual serial ports