Use with a pair of TRENDnet USB to serial converters, connect an RS-232 serial device to the USB port, easy install, universal Plug and Play, TU-S9 Adapter and Additional Tester, GGLABS Mini RS-232 DB9 Monitor and Switching Adapter. Good setup for testing PPP connections between Linux systems. Just don't ask why I need PPP connections ;) Also handy for connecting to DB-9 serial consoles. I like to use a cable, tester and USB serial adapter for this because I can see which signals are active. I overclocked it to 115.2k - I don't remember the speed but it was about 4x faster. Zero errors using Kermit to move a 2MB file.