Before installing conf-isdn-account the packages isdn4k-utils,  xisdnload and dialog should be installed first.  Install them as follows :

Now you can start the tool from the shell-prompt with the command  conf-isdn-account.

Note:  If you use conf-isdn-account to allow other systems on your LAN to access the Internet through your Linux system,  you should configure your firewall correct.  You can do this as follows:

1. Enable the firewall with conf-isdn-account.

2. Disable RedHats ipchains service from the shell-prompt as follows:

   1. service ipchains stop
   2. chkconfig --del ipchains

When necessary,  you can enable RedHats ipchains service again with: