NEED
Many computer systems require lots and lots of I/O. The typical CPU uses
terminal servers to connect PC's to modems. These require all kind of adapters
and associated cable clutter. If a modem line stops working, it is impossible to
troubleshoot the cable nightmare and it is very difficult to switch over to a
backup system. It is very possible that a modem or line is down and the sysop
will never know it or be able to locate the problems.
SOLUTION
Mitsi has developed a feature-rich rack-mountable 4" tall box with 32
RS-232 connections and an intelligent coprocessor. Up to 4 such boxes can be
used in any ISA or Microchannel bus PC yielding a total of 128 modem
connections. Each box can be tri-stated with a button push so that a backup
computer can be switched on line. All of the cable clutter is reduced to a
single cable from the PC going to the switch and a group of 50-pin telco-style
cables that go to the modem banks. Operating system support is available for all
major operating systems. The intelligent coprocessor offloads traffic from
the CPU allowing it to concentrate on SLIP/PPP, newsgroup services and CPU
intensive tasks. A full set of TX and RX LED's and three snoop ports are located
on the front panel to allow a sysop to locate defective modems quickly. The
entire system runs off -48 VDC telco power so dial-up users can get a connection
even during a total power failure that would shut terminal servers down. If your
phone system works, this server will work.
RESULTS
32 modem connections take up less than 4" of shelf space. Up to 128
modem connections are placed in 12" of rack space with a reduction in cable
count of 80%. The telco-cables can be punched down to standard type-66 telco
blocks for easy connection to modem banks. A dual or triple-redundant system can
be added easily by punching down a second or third bank of systems.
Last Updated Fault_tolerant_Internet_server.htm on 01/15/06
