The zaptel drivers and binaries are needed to use popular digital and
analogue telephony equipment and are typically installed alongside the
asterisk PBX (although these are not required for asterisk if you are
not using any hardware to interface with the POTS/PSTN system).  Note
that if you change your kernel after installing zaptel, you'll have to
re-compile zaptel (a simple re-install will not suffice).

The rc script included will handle loading and unloading kernel modules
for you.  By default, it will attempt to load the wctdm module for the
common Digium cards, and if this fails, will load ztdummy to give you
a timing device.  Simply edit the MODULES variable at the top of the
rc script to load other modules if your hardware requires it.  These
modules should *not* be loaded in rc.local or rc.modules, but rather
here, as starting and stopping rc.zaptel will cause these modules to
re-read their config file if you make any changes.

Users outside of North America may find that they need to edit the
zconfig.h file to specify their region's tones.  This script does not
handle that at present.  The statement you'll wish to change is:
  #define DEFAULT_TONE_ZONE=0

The Asterisk Handbook First Edition lists the following zones:
  0 - North America
  1 - Australia
  2 - France
  7 - Japan
 14 - Taiwan
There are many others.  Consult your documentation, or google.

To start zaptel at system boot, do the following:
  # chmod +x /etc/rc.d/rc.zaptel

Also, you'll need to add a statement such as the following to rc.local:
  if [ -x /etc/rc.d/rc.zaptel ]; then
    /etc/rc.d/rc.zaptel start
  fi

rc.zaptel will create a lockfile that is removed when the service is
stopped using this script.  Thus, you should probably put this in
rc.local_shutdown:
  if [ -x /etc/rc.d/rc.zaptel ]; then
    /etc/rc.d/rc.zaptel stop
  fi