The Conexant PCI ADSL Modem is available from several locations at a low cost in New Zealand. World-Net sell it branded as an Access-Runner and it is also available from Dick Smith Electronics as product XH1137. This modem contains a Conexant Tigris chipset and is reasonably easy to get going it linux once you know what to do. The basic steps are below. This is probably going to be quite debian specific seeing as I only run debian.

  1. Build & Configure Modem Driver
  2. Build & Configure PPPoA (PPP over ATM)


The only quirk I have found with the modem so far is that the lights on the back do not go. So if your modem looks dead don't be fooled! Newer revisions of the card (such as those sold by Dick Smith) do not have status lights at all, so this quirk of the driver isn't much of a loss.

Build & Configure Modem Driver

Obtain Modem Driver Source

The authoritative reference for the kernel module that you need seems to be the information below is a summary of this page and a refactoring of the previous information found on this wiki page.

Before compiling the driver you will need to make sure your kernel is compiled with the following options.

 Kernel configuration section   Description   .config Define 
 Networking options   Asynchronous Transfer Mode (ATM)   CONFIG_ATM 
 Network device support   PPP (point-to-point protocol) support   CONFIG_PPP 
 Network device support   PPP over ATM   CONFIG_PPPOATM 

If you are using a 2.6 kernel you also need to ensure that CONFIG_REGPARM is disabled in your kernel. It is also suggested that you turn of SMP and PREEMPT.

You will need to download a different source package depending on the version of your kernel, but after that the process is roughly the same.

The 2.6 drivers have been tested and found to work fine with 2.6.12 by MattBrown

  1. Extract the archive, change into the Directory
  2. make
  3. make install

NOTE: make install tries to install the init script into /etc/rc.d/init.d/ so you might need to edit the Makefile to point it to the correct location for your distribution (ie. for debian, etc.)

This will install some userspace tools for configuring the modem (we'll deal with these in a minute) and also the kernel module. At this point you probably want to run

 depmod  -ae

to update your module dependencies. Under 2.4.26 I get a few warnings about unresolved symbols which is slightly worrying, but everything seems to work ok.

NOTE: You can't just insmod / modprobe the driver, see the following section for how to get it to work.

Configure the Driver

Actually getting the driver to load successfully is another story altogether.

  1. Edit /etc/Conexant/cnxadsl.conf

    • Change the VPI to 0
    • Change the VCI to 100
    • update-rc.d cnxadslctl start 42 S . stop 42 0 6 .

Modem / Connection Status

With the newer revisions of the driver you can issue the following command to get a nice list of stats about your connection (including Sync rates etc).

/etc/init.d/cnxadslctl status

This information comes directly from /proc/net/atm/CnxAdsl:0

Configure PPPoA

The modem driver is now up and running. However before you can actually get on the internet you will need to configure PPPoA.

Setting up PPPoA in Linux is documented on the following page LinuxPPPoA.

Extra Links