In this section, we’ll take a quick look at how to load the zaptel and ztdummy modules without the CentOS initialization script. The zaptel module does not require any configuration if it’s being used only for the ztdummy module. If you plan on loading the ztdummy module as your timing source (and thus, you will not be running any PCI hardware in your system), now is a good time to load both drivers.
In the early days of Linux, the system’s /dev/ directory was populated with a list of devices with which the system could potentially interact. At the time, nearly 18,000 devices were listed. That all changed when devfs was released, allowing dynamic creation of devices that are active within the system. Some of the recently released distributions have incorporated the udev daemon into their systems to dynamically populate /dev/ with device nodes.
To allow Zaptel and other device drivers to access the PCI hardware installed in your system, you must add some rules. Using your favorite text editor, open up your udevd rules file. On CentOS, for example, this file is located at /etc/udev/rules.d/50-udev.rules. Add the following lines to the end of your rules file:
# Section for zaptel device KERNEL="zapctl", NAME="zap/ctl" KERNEL="zaptimer", NAME="zap/timer" KERNEL="zapchannel", NAME="zap/channel" KERNEL="zappseudo", NAME="zap/pseudo" KERNEL="zap[0-9]*", NAME="zap/%n"
Save the file and reboot your system for the settings to take effect.
You may not have to actually edit anything in your system, as the Zaptel installation script will try to install the rules for you; however, we have left this here as a reference for those systems that are not automatically configured.
The zaptel module must be loaded before any of the other modules are loaded
and used. Note that if you will be using the zaptel
module with PCI hardware, you must configure
/etc/zaptel.conf before you load it. (We will
discuss how to configure zaptel.conf for use with
hardware in Chapter 4, Initial Configuration of Asterisk.) If you are using
zaptel only to access ztdummy,
you can load it with the modprobe
command, as follows:
# modprobe zaptel If all goes well, you shouldn’t see any output. To verify that the
zaptel module loaded successfully, use the lsmod command. You
should be returned a line showing the zaptel module
and the amount of memory it is using, as in the following:
# lsmod | grep zaptel
zaptel 201988 0The ztdummy module is an interface to a device that provides timing, which
in turn allows Asterisk to provide timing to various applications and
functions that require it. Use the modprobe command to load the
ztdummy module after zaptel
has been loaded:
# modprobe ztdummy If ztdummy loads successfully, no output will
be displayed. To verify that ztdummy is loaded and
is being used by zaptel, use the lsmod command. The following output is from a
computer running the 2.6 kernel:
# lsmod | grep ztdummy
Module Size Used by
ztdummy 3796 0
zaptel 201988 1 ztdummy
If you happen to be running a 2.4 kernel-based computer, your
output from lsmod will show that
ztdummy is using the usb-uhci
module:
# lsmod | grep ztdummy
Module Size Used by
ztdummy 3796 0
zaptel 201988 0 ztdummy
usb-uhci 24524 0 ztdummy