I am looking for a specific type of hub that is connected to the
Ethernet network and then offers multiple ports as output that are
serial ports and recognized by the primary server as additional serial
ports. Systech makes such a device, but it seems terribly expensive.
Following is from their description "The unit connects to the LAN and
gives you 1, 2, 4, 8 or 16 serial ports.  The ports are all software
selectable to RS-232, 422 or 485.  The port redirection software,
NativeCom, loads up on the various pc?s and/or the host and makes our
ports appear as local com ports to the pc?s/host even though the unit
is anywhere you need the connectivity.  The serial devices hang off
the Systech ports but appear to the application as if they are
directly connected to the motherboard of that particular pc/server. 
Product features also include SSL encryption, TCP/IP routing, PPP
Async Communications, remote flash update of complete configuration
settings and web-based diagnostics and troubleshooting." This is to be
used in a point of sale application and we are just looking for back
up parts from someone other than this company whose prices range from
350.00-700.00 for these units.