[Discuss] getting a USB modem working with Linux

[tmetro+blu at gmail.com (Tom Metro)]

MishaStrGm wrote:
> I got Usb- Rj11, Usb - phone line modem.
> Zoom 3095

You explained off-list that you had two USB modems: a Zoom 3095 and a
Trendnet TFM-561u.

I was surprised to see that the Linux Modem HOWTO[1] says that even
("new" style) external USB modems[2] can be built like "winmodems"[3]
and require special drivers that implement a portion of the signal
processing.

1. http://www.tldp.org/HOWTO/Modem-HOWTO.html
2. http://www.tldp.org/HOWTO/Modem-HOWTO-2.html#ss2.9
3. http://www.tldp.org/HOWTO/Modem-HOWTO-2.html#soft_modem

My recommendation is that you do examine the output from lsusb to
identify the modems at the hardware level. You could do this using
commands like:

With no modems attached:
% lsusb > no-modems

Then plug in the Trendnet modem, and run:
% lsusb > trendnet

And now see what changed:
% diff -u no-modems trendnet

Post the results in a reply here. Repeat this for your Zoom modem.


The 'lsusb' output will be like:

Bus 002 Device 005: ID 064e:a117 Suyin Corp.

The device identifier (like 064e:a117) can be used in a Google search
along with "linux" or "ubuntu" to often turn up discussion of how other
people got drivers working for that device.


Off list you wrote:
> i try to install Zoom 3095.
> Gnome PPP tell error, no dial sound.
> It does not look that modem is working.

Trying to get PPP working is skipping ahead. You might have gotten
lucky, but it should be easier to troubleshoot by running the more basic
modem tests that are mentioned in the Modem HOWTO.

But the first step is figuring out what serial device the modem is
appearing as (either using the kernel's built-in USB serial driver, or
the emulated serial interface provided by the "winmodem" driver). Until
you do that, and determine whether you need to install a specialized
driver for it, you can't really proceed to trying modem applications
like PPP.

My modem knowledge with Linux is very rusty. Anyone with more current
knowledge that can give this user some guidance?

(Just recently I briefly wrestled with trying to get a couple of
"winmodems" built-in to laptops working, with the idea of using them
with Hylafax to send faxes, but the probing script provided by
linmodems.org failed to definitively identify the modem hardware. It's
best guess on one laptop was that the modem hardware was piggybacked on
the Intel high definition sound hardware built-in to the chipset.)

 -Tom

-- 
Tom Metro
The Perl Shop, Newton, MA, USA
"Predictable On-demand Perl Consulting."
http://www.theperlshop.com/