Although
they're called "terminal servers", most -- including
all the ones
I've mentioned -- can be configured so you
telnet in to them and make a
serial connection out to one of the serial ports, which looks to the
machine it's connected to as if a serial terminal has connected
to it. On
This can also be done with a Linux box (a homebrew terminal server).
Multi-port serial cards can be found for very reasonable prices.
I'm sure there's a package that someone's already written to do this too.
There's 3Com CS/3100 (48-port serial to/from ethernet) on ePay that
currently has no bids. If it's worth the $25 trade-off (vs multiport serial
cards, Linux shell scripts, etc.) to whoever originated this topic (and no,
it's not my auction). Free docs on the 3Com web site.