LTModem Drivers for Linux

On this page you'll find Linux driver (sources, binary packages) and documentation for so called Winmodems with Lucent Apollo (ISA) and Mars (PCI) chipsets. Lucent AMR modems are not supported by this driver. The core communications code of these kits is the property of Agere Systems, Inc. (formerly known as Microelectronics Group of Lucent Technologies). The driver was developed and is maintained by Soumyendu Sarkar at Agere Systems, the open source parts were modified by Mark Spieth, Marvin Stodolsky and Christoph Hebeisen to implement some additional features.

Should you need help installing or using the driver or have any other questions about it, please consult the mailing list archives (searchable here) and the available documentation before posting a question to the mailing list. More general issues concerning Winmodems are presented in the Linmodem HOWTO. All technical questions and suggestions should be sent to the mailing list.

DISCLAIMER: This software comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. Therefore no liability will be assumed for any damage including (but not limited to) system crashes, loss of data, hardware failure, loss of business and all other direct or consequential damage that may result from the use of this software.

WARNING: While the driver is working on most systems there have been reports of system crashs due to resource conflicts. Therefore it is strongly discouraged to load the driver at boot time since this might render your system unbootable in case it is affected by this problem.

Binary Packages

If you are new to linux, these packages are probably what you will want to use if it is available for your specific configuration. They are precompiled so they avoid the hassle of compiling the driver from source.

These binary drivers will only work with the kernel version and configuration they have been built for, i.e. stock kernels of the respective distributions. Do not use them with custom kernels. Due to disk space limitations I only keep recent versions of the binary drivers for current kernels here. Older versions can be found in Jacques Goldberg's archive.

WARNING: The contents of the binary packages have not been verified so if you have to be paranoid about the security of your system it is advisable to compile the driver from source yourself.

Debian GNU/Linux

If you're using Debian GNU/Linux these are the right binary packages for you. Download from Germany or Canada and install them using dpkg -i . The syntax of the filename is ltmodem-KVERSION_LTVERSION_i386.deb where KVERSION is the version of the kernel the driver is matched to (as in the output of uname -r) and LTVERSION is the version of the driver.

Alternatively you could add one of the following two lines to your /etc/apt/sources.list and let apt-get do the rest for you:

deb ./
deb ./


LTModem is part of the gentoo package system, so you can just run "emerge ltmodem". This will download the source, configure,compile,and install the module.

Red Hat Linux

Look for your driver here if you are using Red Hat Linux. Download from Germany or Canada.

Fedora Core

Fedora is Red Hat's "consumer-level" operating system: Fedora Core. Download ltmodem rpms from Germany or Canada.

Mandrake Linux

Here are the drivers for Mandrake Linux. Download from Germany or Canada.

SuSE Linux

SuSE Linux includes the ltmodem driver (9.0 and later). Please install the driver that comes with your distribution because it's guaranteed to match with your kernel.
Older binary drivers can be downloaded from Germany or Canada.

Conectiva Linux

RPMs for Conectiva Linux systems are available here: Download from Germany or Canada.

RPM missing?

Except for Debian GNU/Linux I can only supply contributed packages. So if you happen to run a stock kernel / distribution combination for which there is no binary package yet, please build an RPM and send it to me.


For build instructions read the file 1ST-READ which is contained in the package.
There is a beta source tarball (thanks to Aleksey Kondratenko) for 2.6 kernels, served from Jacques Goldberg's resource page.

Download from Germany Download from Canada Description
ltmodem-8.26a.tar.gz ltmodem-8.26a.tar.gz For use through kernel versions 2.4.20
It does in fact fail for some RedHat 2.4.21, for lack of the fedora fix
ltmodem-8.31a10.tar.gz ltmodem-8.31a10.tar.gz Debian binary build fixed
ltmodem-6.00c.tar.gz ltmodem-6.00c.tar.gz This is the latest version of the driver that will work with 2.2 kernels.
PCMCIA PCMCIA Support for ltmodem PCMCIA cards in configurations with non-transparent PCMCIA bridges (e.g. Texas Instruments). Contributed by Jörn Wüstenfeld.

Older drivers can be found in the archive.

Common Problems and Solutions

To build a driver from source code you will need to install the full (and configured) kernel source, only the kernel headers are not enough. If the build fails on your computer with error messages referring to kernel headers that should not be used to build kernel space drivers this is most probably the reason why. For more detailed information please read this email.

Another very common problem are kernels with "kernel flavour" name like e.g. the notorious SuSE 2.X.Y-4GB problem which leads to version mismatch errors on inserting the modules. A workaround is described here.
Note that the fixscript that is linked in this posting is outdated. Please use the newest version of the fixscript.
You could also just change the version number in linux/include/linux/version.h from 2.X.Y to 2.X.Y-4GB which is also known to work but deprecated since one should generally avoid changes to header files that come with the distribution; maybe after all SuSE has a reason to deliver a version.h that is mismatched with the kernel images they deliver.


For the technically savvy, there's some advanced technical information about the code from Mark Spieth that you might want to read before considering to write a patch.

The periodically updated Ltmodem.html addresses most questions about installation and compilation.

Here's some information about the 5.99 resp. 6.00 version of the driver from Lucent including AT commands etc.

DOCs.tgz contains a growing scrap collection of advice excerpted from the mailing list and other sources. The 1ST-READ therein advises on modem types which are not or may be serviced by the resources on this site. Much of the contents DOCs.tgz are of broader applicability than just for ltmodem. Check periodically for updates. It should be unpacked only under UNIX with command: tar zxvf DOCs.tgz. More specifically: don't use any windows program like Winzip or similar.

Jacques J. Goldberg has written a post-install tutorial which will be helpful if you have successfully installed the driver but still have problems connection to the internet.

There is also a pretty comprehensive newbie guide to the LTModem by Daniel Rees which addresses most issues that come up over and over again on the mailing list.

Claudio Cescutti has written an installation guide in Italian.

There is a Portugese translation of the information on this page by Antonio Sergio.

All trademarks and copyrights on this page are owned by their respective owners.
Bandwidth and space kindly provided by PhysCIP Universität Stuttgart and Simon Fraser University.
Page maintained by Christoph Hebeisen

Mon Jan 31 01:35:10 EST 2005