This is the main page for ISDN 4 Linux

For the old homepage (with possibly useful old information), please go to

Hardware support

passive ISDN cards

The well known HiSax driver is now obsolete. To use passive ISDN cards, you
can use the new mISDN driver.

You can find information and documentation on its own page

active ISDN cards


Please go to for Isdn4Linux mailinglists and archives.
The old archives can be found here .


Currently you will find the FAQ at


Get links for download from here:

CVS access

The ISDN4Linux CVS repository can be accessed in several ways:

  • Anonymous access using the pserver method with any cvs client.
    Use the following commands:
    cvs -d login
    cvs -d co isdn
    When asked for a password during login, enter "readonly" (without the quotes). Instead of isdn you also can check out other modules like isdn4k-utils, mISDN, mISDNuser, NGC4Linux or web.
    For a more detailed description, have a look into the FAQ.