[ale] NewbieQs on 'tethered' net connections

[Sean C. McCord]

On Mon, Apr 20, 2009 at 05:43:49PM -0400, Mills John M-NPHW64 wrote:
>ALErs -
>
>1. Is there a HOWTO on this that can suggest specs and models of low-end phones for net access from my Linux laptop? 

As far as I know, ALL GSM phones (those of AT&T and T-Mobile, in the
USA), can serve as a modem.  I have used it in all my phones since my
first one with Powertel who knows how many years ago.  That said, you
have a few things to look for:

a)  The phone has to have some method to _get_ to your laptop:  Wifi,
serial, USB, etc.
b)  If your phone is "locked" (that is, it was bought from the
carrier), it may be restricted in some way, so all bets are off.

>2. If my phone account doesn't provide a direct net connection of some kind, is it practical to telephone my ISP's dial-in modems and run that way?

You don't necessarily need a "direct" net connection.  For years, I
used T-Mobile's proxies access for $4.99/mo.  The only reason I
changed is because I got a Google Phone and wanted full, unrestricted
access for VPN, SSH, Email, etc., without having to funnel everything
through a hacked up port 80.

>Some notes make it look just like setting up PPP through a modem and others seem more like a network link. I have a couple of half-*ssed ideas about what's going on, but nothing solid.

For GSM (I have no clue about CDMA, i.e., Sprint, MetroPCS, Nextel,
Verizon, etc.), the phone acts like a modem.  You interface to with
with a slightly special AT command set, so to the computer, it looks
just like a modem.  You even dial up and "connect" just like expected;
and yes, it is a PPP connection.

If you are using a special app some of the fancier Wifi-enabled
phones, it is going to act more like a wireless access point.  You
won't be PPP'ing, most likely.  It will just look like a normal TCP/IP
link over wireless.

--
Sean C. McCord
CyCore Systems
scmlist at cycoresys.com