Virtual Serial Port / Tunneling

2 Linux servers (Server 1 (elmo) & Server 2 (oscar) -- assume RHEL ES4
if needed) with network connections on different subnets, each with a
a Digi AccelePort Xem with 16-port RS-232 RJ-45 concentrator (/dev/
ttyx0 - ttyxf) attached. Muti-Tech modems for inbound & outbound
faxing will be attached to serial ports on each server. Will be
running HylaFax to send out faxes to the various tty ports.

Oscar acts as D/R for Elmo. However instead of paying for lines &
modems to be utilized as D/R, I would rather use them for production
and accept the reduced capacity if we had to fail over to D/R.
Therefore, I am wanting to find out if there is a server software that
will allow me to share the local specified TTY over TCP/IP. And client
software that will allow me to virtualize a local port to the shared
TCP/IP port on the other server. So in this case, Oscar would need the
serial to ethernet server enabling and Elmo would need the virtual
client to map it as a local serial port.

I understand that there are plenty of serial over ethernet servers
with proprietary client software to create virtual serial ports on
linux/win workstations or servers. However, I already have the serial
cards for these servers purchased and would rather use what I have
than buy something standalone allbeit preferred.

Thanks in advance!