Recommendations for a data-only GSM/UMTS device in USB stick ff

Brian bneil at
Sun Nov 20 00:31:42 CET 2011

On Sat, 19 Nov 2011 21:51:33 +0000
David Pottage <david at> wrote:

> On 15/11/11 01:24, Michael Sokolov wrote:
> > * I need this device to be capable of placing old-fashioned data
> > calls, not just Internet access.  By old-fashioned data calls I
> > mean the arrangement where one dials a number from the mobile
> > device with ATD<number> (no semicolon at the end, making it a data
> > rather than voice call), and the number being dialed is a POTS land
> > line with a plain old analog modem answering the call.  I want to
> > be able to connect to my personal data center from remote locations
> > bypassing the Internet.
> I think you will find that it is imposible to make data calls to an
> analoge modem. The reason is that GSM and it's sucessor standards are
> inherently digital, and are derived from ISDN telephone standards, so
> nothing in your phone or in the phone network will create tones that
> will be understood by an analogue modem.

I don't know about doing that with GSM but it 'sort of works' over VoIP
which is also inherently digital. I had occasion to help a guy out with
transitioning from Windows Vista to Ubuntu (iirc) and he only had
Dial-Up. I only have VoIP and have done for years but did manage to
figure out the proper methods to use for him to be able to use his ISP
when they wouldn't support it.

I had a friend who also uses VoIP test a kermit connection with me. It
worked but it wasn't very reliable or error free. That wasn't the goal
though, initially I just wanted to verify that the hardware modem would

After verifying it worked I did manage to surf the web albeit at lower
than the 56k speeds the modem is capable of but it did work. I probably
could have fiddled around with asterisk a bit more and utilized fax
instead of voice but I was only interested in determining the proper
login procedure for his ISP.

> Having said that, there should be no problem making data calls to
> another GSM device or a digital trancever on the end of an ISDN phone
> line.
> Given your other requirements for off the shelf hardware, I think your
> simplest solution would be to buy a mobile phone with a data port, and
> learn how to use that port as a GSM modem. For example I used to work
> for Nokia, and I know that with their phones, if you put them into "PC
> Suite mode" they will respond to AT commands on their serial/usb ports
> and let you do dial up internet to your ISP, or any other phone
> number. You may find that your current phone does what you need.

Good luck in your endeavors.


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