Linux serial relay

[dmcmorris]

I have this fictional scenario that I may try to play out to see if it works.

I want to relay a serial port from location A to location B.

Location A has a device that you would hook a terminal up to via serial port (IE: a smart switch that you would hook to your computer and use a terminal emulator to administer it).

Location B has a dumb terminal.

Using 2 Linux computers (1 at each end), I want to be able to administer that switch through the dumb terminal just as I had it hooked directly to the switch.

For the purposes of this discussion, assume that the systems can freely communicate via TCP/IP (such as over a VPN). Using a dumb terminal in Linux to ssh to the other linux box and then minicom to the serial port is not an option.

Basically, anything sent IN the serial port at Location A must come OUT the serial port at location B UNMODIFIED.

For now, there is no real practical situation I have in mind. It is more-or-less to broaden my knowlege of linux a little bit.

Would be cool if I had a computer here in the US that had a serial-serial connection to a linux PC, and dialed out on a 9600 baud modem in australia, as if it were directly connected to the american PC. Fairly pointless, but cool none the less.

[lnxmatt]

This isn't exactly a linux based solution but I've setup a similar system. I purchased two RS-232 serial-to-ethernet adapters (small device with DB-9 serial on one side, and RJ45 ethernet on the other) for remote monitoring of a serial device. I had a router onsite configured with a VPN tunnel back to our main office where I had my monitoring workstation. I connected one of the adapters to my serial device and the other to my workstation at the main office, configured them for "tunnel" mode, and through TCP/IP all the serial data was transfered from the remote site to the main office workstation. This solution worked really well and is still working today for monitoring and configuration of said serial device.

[dmcmorris]

I've seen those! They seem pretty cool. Thing is, I have a surplus of computers. If I was able to use them as a serial relay, I thought it would be kind of cool. No practical use comes to mind right off... Perhaps using a dumb-terminal to monitor a remote switch that coninuously had the status dumped on the screen... or (again using a dumb-terminal) monitoring the KSU of a switchboard...

Although, in both of these scenarios, it would usually be acceptable to use a linux system to host the dumb terminal, SSH'ing to the remote system, and using MiniCom to use the serial port. I just wanted to know how to do the above more for my knowlege... even if it won't ever be used in a production environment...