Thanks for the suggestions. Spartacom used to make SAPS so yeah that is really what I'm looking for. You're right, the Equinox box is probably not quite I'm looking for.

The Spartacom stuff has pools meaning you can have one COM port on the client and that automatically selects the next free server port - the user doesn't care which comport he gets. The Equinox seems to map a COM port on the server end to a com port on the client. So for each comport on the server, you'd need a comport on the client. Correct?

However the operative word is free or cheap. The Spartacom stuff is US$1k which might not seem expensive to you, it is expensive for us, since my boss won't spring for something he can't see a financial advantage in - Not easy to bullsh** him either.