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Serial over IP

  Date: Dec 04    Category: Unix / Linux / Ubuntu    Views: 2256

I would like to control a serial modem remotely over my LAN
and figured since my Linux fileserver is turned on 24/7, that
I might be able to use it to pipe (right term?) my modem over
the network.

Lots of google and forums searches later, I have serious doubts
as to whether this is possible. Of course with Windoze it's
trivially easy but the closest I was able to get for a Linux
solution was to buy a commercial package costing hundreds of

It appears the best solution is a basic serial to IP converter
box you can get from any number of vendors (Black Box, et al)
but thought I'd run it past the group to see if there might be
some solution out there for Linux I'm missing. Seems like it'd
be a relatively common activity but maybe not.



11 Answers Found

Answer #1    Answered On: Dec 04    

Open up synaptic package manager and look at the following programs:
"packit", "ser2net", "cereal" "vtun"

I don't know if any of these are quite what you want, but their description
seems to be related to what you want. I just opened up synaptic manager and
searcher for serial to ip... my appologies if you have already done that and
didn't find anything useful there.

Also, Does one of these not do what you want?


Not coming from the repositories, or course, there is no way to say w/o
looking at the code what the integrity of the products/sites are. But may
be worth looking into?

Answer #2    Answered On: Dec 04    

I was looking at ser2net
but couldn't figure it out (I'm not a linuxhead). But knowing
it has a package for Ubuntu gives me justification to at least
give it a go and see how far I get. The others don't have
packages that I can tell. I don't know how to compile nor do
I have the time or inclination to learn, so I guess that might
have to wait until "someday".

Answer #3    Answered On: Dec 04    

I typed in modem in Synaptics and found many modem control apts. Not
knowing what you are trying to control I wouldn't know what to search
for. AT commands are what control most modems so a simple CGI script in
any lanquage should do what you want by sending the proper AT commands.
If what you want is simple enough a programmer acquired through rent a
coder on the net should get you going without emptying the bank.

Answer #4    Answered On: Dec 04    

I'm not so much looking for "modem control" as much as I am
creating a "tunnel" or "pipe" (not sure of the correct noun)
of a serial port on one box on the network, to a virtual com
port on another. While one use would be a modem I actually have
a number of serial devices I'd like to control if I could get
it to work.

At my place of employment we use serial "hubs" to IP to
embedded linux hosts which works slick, but that's a spendy
solution for a hobby setup at home. Digi I/O makes them I
think, as well as Black Box.

Answer #5    Answered On: Dec 04    

Do you need interrupt control, or can you program your serial devices to
communicate using an address scheme and one serial port i.e.
transmitting a key word that the device will act on.

If not then use a serial card to communicate using many com ports mapped
in a table. Likely Linux will map any serial ports you have installed
on your box. I don't know this for sure, but I can't believe it fails
to register all serial ports.

Each different device has it's own control language, as does a modem. I
like using the PIC line of controllers myself, with my own programmed
control words to wake them up. They listen on a single serial bus and
act on commands when they hear their key word for the next command chain.

Like I said, if your devices are not standard, communication should be
supplied by the manufacture in the form of a driver with documentation
for communicating with them. If they are standard in the form of
"Popular" the drivers may be in the kernel. So, what you trying to do?

Answer #6    Answered On: Dec 04    

There was a time when my specialty was making modems dance to my tune, but I
would not have said this was trivially easy in Windows. Could you give a hint on
that, please?

Dial-up in Linux is a PITA, let alone on a remote machine.

Answer #7    Answered On: Dec 04    

Actually I recently signed up for a dialup account to experiment with
multiple gateway routing on linux, and so in the process I had to set up
dialup networking, which I hadn't worked with since the 90s.

I found the modem setup on ubuntu to be relatively straighforward -
certainly more so than it was 15 years ago. I ran into a snag or two,
but the problems were quick and easy to resolve and I was up and running
on my ppp account within a quarter of an hour.

Once set up, it's a simple point and click to start up ppp and get on
the internet.

Answer #8    Answered On: Dec 04    

Ultimately the dialup or serial device data would be processed
through the local machine, irrespective of OS. The remote linux
box would convert the COM port to an IP address and port, which
can be viewed by the local machine as a virtual COM port.

Answer #9    Answered On: Dec 04    

I'm one of the dial-up diehards - and doing something that sounds very close to
what you're trying to do.

My serial modem is connected to an old computer running "Smoothwall Express", an
Open-Source firewall package.


My Smoothwall PC runs "headless" - no keyboard or monitor. I get to it via a
web browser running from any other computer on my LAN. Dial-up support in
Smoothwall is a bit quirky, but it does work. I'm very happy with it, and I get
a much better network topology than I had before. Doesn't take much to run it:
I'm using a late-20th century 566Mhz Celeron with 256MB RAM and a 4GB HDD.

If I were still the geek I used to be, I'd combine that software with my file
server, and set up that box as a print server, too...

Might this be the solution you're looking for?

Answer #10    Answered On: Dec 04    

Not that I like
dialup, but computers aren't my life and I can't see spending
many hundreds of dollars a year on broadband.

I did see smoothwall in my quest, and I'm keeping it as a
contender if I can't get anything else to work. The downside
is it would need a dedicated machine, which might be an option
but I'm running too many dedicated machines as it is. Even
when they're "free" old pentium 500's or whatever they still
have fans, hard drives and take up shelf space. Was hoping
to piggy back the solution on a machine I already have running.

Answer #11    Answered By: Jose Valle     Answered On: Jan 10

1. install ssh server on your linux box
2. then install minicom..http://alioth.debian.org/projects/minicom/ and configure it with the right serial port, speed, parity and etc. to interface with your modem

3. To access from a remote place, you can use putty as an ssh client, from thereon run minicom so you can access you modem. You can even use a mobile phone with wifi and java version of ssh client to access you serial modem...

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