Specifications

©
2002, David K. Z. Harris
13
Pg. 13
© 2002
David K. Z. Harris
Terminal & Console Servers
Ø Terminal Servers were designed
to allow ‘dumb terminals’ to
access hosts on IP networks.
Ø Reverse Telnet allowed users on
the network to connect to serial
ports on terminal servers
Ø Console Servers are a newer,
enhanced Terminal Server,
meant for supporting console
access.
Terminal servers are still readily available, and you can pick them up fairly
cheaply on eBay, or other dot.com auctions.
However, Terminal Servers didn’t need to care about Serial BREAK in the old
days, and sometimes it was designed to send BREAK when sessions cleared up
(to reset a modem, for example). So an older unit may send Serial BREAK to
attached devices under some conditions. If you have SUN computer consoles
attached to your terminal server, a BREAK can halt your SUN.
Serial BREAK is actually a Good Thing, in moderation, and useful for
administration of your hosts. You can get more information from my Serial
BREAK-off testing pages, http://www.conserver.com/consoles/breakoff.html
Newer Console Servers are generally better about not sending Serial BREAK at
the wrong time, but if you have SUN gear, you should make sure that the
equipment you are buying is marked “Sun-safe”, or otherwise states that it
won’t send Serial BREAK unless you want it to.
Console Servers also typically have better documentation for their
implementation of the reverse-TCP connection, and more features for remote
access than ‘terminal servers’.