[mdlug] It happened...

[Joseph C. Bender]

Ingles, Raymond wrote:
>> From: Carl T. Miller
> 
>  I imagine Windows Mobile phones can do that, too. I dunno about Blackberry
> or Symbian phones, but I wouldn't be surprised. 
 >
	Yes to both the Symbian and Blackberry devices, though almost all of 
those won't attempt a data call without the provider telling the phone 
they're allowed to be a tethering device (at least on CDMA)

	Of all of these, if you can get something on a CDMA carriers, from a 
speed and latency perspective, it's worth it.  I'd stay away from 
Verizon, as they have been enforcing major caps on how many bits you 
move on their network (which is a rant for another time).

EDGE data service on a GSM carrier (T-mobile, AT&T) is okay, but not 
terribly fast or with decent latency.  If you're in a contract with 
either of those, it does work for casual use.

 > You can also get PCMCIA cards
 > that let a laptop connect directly to the cell network... though
 > I don't know how many of those are supported by Linux.
 >
	If it's a Cardbus EVDO card or USB widget, almost all of the time 
they're using some implementation of a Qualcomm chipset.  The Cardbus 
cards are actually Cardbus-USB bridges that just implement another USB 
controller so the internal USB interface on the card has something to 
connect back to the host with.  All of those devices enumerate in Linux 
such that anything with hotplug running (which most recent distros do 
out of the box, unless it's particularly lame) will detect and load the 
cdc_acm kernel module, with the device showing up as /dev/ttyACM0. 
Phones will either show up as ttyACM or ttyUSB, depending on how the 
phone presents itself on the USB.

	That being said, there's performance problems using the cdc_acm module 
with the EVDO cards, it's kinda inefficient with the speeds they 
actually get (generally higher than cdc_acm was expecting).  That has 
improved in recent kernel releases.  There's a workaround where one can 
either change what hotplug loads, or manually unload cdc_acm and load 
the usbserial with some custom options.

-- 
Joseph Bender
Bendorius Consulting
P: 248-434-5580
F: 248-434-5581
jcbender at bendorius com