[clug] Virtual serial ports

Daniel Pittman daniel at rimspace.net
Wed Apr 21 21:00:23 MDT 2010

steve jenkin <sjenkin at canb.auug.org.au> writes:
> Adrian wrote on 22/04/10 9:39 AM:
>> I have a dual serial RS232 port to Ethernet converter. I need to run 2
>> minicom session on a machine that will talk via two virtual serial
>> ports, then over IP to the converter. I understand that there is a
>> common standard for doing this and thus I hope that the hardware I have
>> supports this standard. I cannot locate the Linux drivers or how to
>> create and install such a virtual serial port.  Any suggestions?

Normally, we just configure the serial-to-net device with the right port
rate and flow control, then use plain TCP connections[1] to talk to it.

If you need access to the control lines, or to dynamically change those
parameters, I don't know of any good client software — and there is no kernel
driver for the RFC2217 protocol to the best of my knowledge.

That said, I think the protocol extensions to telnet were pretty light and you
should be easily able to send and negotiate them in you favorite scripting
language or telnet library...

> something like 'netcat' from the receiving end back into the serial-ethernet
> device will work, depending on what you want to do, like capture the output
> of some monitoring devices.  (it's a terminal server by another name)

*nod*  That normally works for us.


> There's gotta be a good reason you couldn't use a USB-serial adaptor, you're
> no fool and you're work needs good/leading-edge engineering solutions :-)

Those are ... not as robust or reliable as you might hope.  An amazing number
of vendors don't include a serial number in the device, so you can't
distinguish between them if you have more than one USB serial device
connected, for example.


[1]  ...or connect over SSH, depending.

✣ Daniel Pittman            ✉ daniel at rimspace.net            ☎ +61 401 155 707
               ♽ made with 100 percent post-consumer electrons

More information about the linux mailing list