ADSL usb modems

[Rick Stevens]

Graeme Nichols wrote:
> On Sat, 2004-05-01 at 02:59, Rick Stevens wrote:
> 
>>Graeme Nichols wrote:
>>
>>>On Tue, 2004-04-27 at 02:32, Rick Stevens wrote:
>>>
>>><snip>
>>>
>>>>There are some ADSL modems that work fine with Linux and some that
>>>>don't, just as there are some winmodems that work and others that won't. 
>>>>Keep in mind that this is not just a Red Hat issue--it's a general Linux
>>>>issue with manufacturers not helping an open source solution.
>>>
>>>
>>>Do you have the names of those usb ADSL modems that DO work with Linux,
>>>or point me in the right direction to find out?
>>>
>>>I am a bit disappointed to learn that there are not only 'gutless'
>>>dial-up modems out there but 'gutless' ADSL modems as well. The way
>>>things are going, the next time one buys a new car the engine and drive
>>>train will need to be supplied by the 'driver' :-)
>>
>>http://www.linux-usb.org/ is the list of USB stuff.  I don't know if
>>they have USB cable or DSL modems, but you can check.
> 
> 
> Hello Rick, they didn't have all that much. I finished up buying a
> Billion BIPAC-5100 ADSL Modem/Router and a Dolphin PCI 6003 Ethernet
> 10/100Mbps Ultra Power Series nic. As well as the Windows logo it has
> Tux as well on the box. Amongst all the bulleted features it claims is
> the following: 'Supports the widest range of drivers for common network
> systems such as Novell, IBM, Windows, SCO Unix and Linux.' So, it should
> be OK.

That's fine.  In my experience the most compatible (and stable) set up
is a stand-alone modem (cable, ADSL, whatever) with an ethernet port,
a separate router/firewall (I use D-Link units, but Linksys and others
are good except for Belkin), and either WiFi or hard-wired ethernet.

NEVER use Belkin firewalls or routers.  After that last debacle where
the firmware would periodically "steal" one of your connections and
route you to an advertising site, I wouldn't trust them as far as I
could throw their corporate office building.  B*stards!

> The router was the Editor's Choice in an APC magazine article on such
> devices last February so I fully expect it to function OK.

I'm not familiar with that make (Billion), but if APC says it's good,
then I'd feel fairly comfortable.  I don't use DSL myself (I use cable
modem--I'm too far from the central office for DSL to be worth it), so
any comments I make would be anecdotal at best.

> The freebie ADSL usb moden supplied by the ISP is a D-Link DSL 200 and
> according to the D-Link web site only supports Windows (only Windows
> drivers available) so it is akin to a 'winmodem'

Yup.  I have several friends at D-Link and I'm trying to get them to
start supporting things on open source more.  The problem is that the
makers of the chipsets they use (Texas Instruments being the worst
offender) supply the drivers to D-Link in binary form so not even they
can play with them without reverse-engineering them.

> The article I mentioned above strongly suggested to avoid ADSL usb
> modems as they "suck CPU power; they don't always co-exist peacefully
> with other usb devices; they need special drivers for each operating
> system; and they are incompatible with some motherboard chipsets and
> BIOS firmware. Ethernet has none of these disadvantages."

This isn't always true.  It depends on how the thing is made.  If it
depends totally on the USB bus to power it (like a FLASH stick), then
yes the power concerns are big.  Due to the processing they do, they can
hang the USB bus at times, too.  As far as I'm concerned, I only use USB
for the things it was really intended for...connecting storage devices
and HID.  I don't use it for networking.

> One last question, Have you, or any one else, had any feedback on
> Dolphin nics? The vendor, Dick Smith Electronics, claim they have never
> had any complaints.

It rather depends on the chipset used on the card.  If it's a "name
brand" (3Com, Intel, DEC, etc.) you should be OK.
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- Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
- VitalStream, Inc.                       http://www.vitalstream.com -
-                                                                    -
-      A day for firm decisions!!!   Well, then again, maybe not!    -
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