Without going into the long of it, currently a client of mine has two sets of POS terminals in two separate buildings, which are connected via the local IP network and the analog PBX system for voice. The POS system communicates with a PC for collection of information, and that PC is in building A. There are also POS terminals in building B.

The POS terminals use RS232 to communicate with the PC. Right now, we are using a line over the analog PBX system and modems to bridge the gap between the buildings. Does anyone know of either an RS232 over IP or a USB over IP (using USB-Serial adapters) that is reliable enough to use in production? Ideally something software based that could be run on an existing PC in building B and the VM that does the collection in building A.