System information

DAHDI

The Digium Asterisk Hardware Device Interface, or DAHDI (formerly known as Zaptel),

is the software Asterisk uses to interface with telephony hardware. We recommend that

you install it even if you have no hardware installed, because DAHDI is a dependency

required for building the timing module res_timing_dahdi and is used for Asterisk

dialplan applications such as MeetMe().

DAHDI-tools and DAHDI-linux

DAHDI is actually a combination of two separate code bases: DAHDI-tools, which

provides various administrator tools such as dahdi_cfg, dahdi_scan, etc.; and DAHDI-

linux, which provides the kernel drivers. Unless you’re only updating one or the other,

you’ll be installing both at the same time, which is referred to as DAHDI-linux-com-

plete. The version numbering for DAHDI-linux-complete will look something like

2.4.0+2.4.0, where the number to the left of the plus sign is the version of DAHDI-

linux included, and the version number to the right of the plus sign is the DAHDI-

tools version included.

There are also FreeBSD drivers for DAHDI, which are maintained by the community.

These drivers are available at http://downloads.asterisk.org/pub/telephony/dahdi-freebsd

-complete/.

Another dependency is required for installing DAHDI, and that is the kernel source. It

is important that the kernel version being used match exactly that of the kernel source

being installed. You can use uname -a to verify the currently running kernel version:

• CentOS: sudo yum install kernel-devel-`uname -r`

• Ubuntu: sudo apt-get install linux-headers-`uname -r`

The use of uname -r surrounded by backticks (`) is for filling in the currently running

kernel version so the appropriate package is installed.

The following commands show how to install DAHDI-linux-complete 2.4.0+2.4.0.

There may be a newer version available by the time you are reading this, so check

downloads.asterisk.org first. If there is a newer version available, just replace the version

number in the commands:

$ cd ~/src/asterisk-complete/

$ mkdir dahdi

$ cd dahdi/

$ svn co http://svn.asterisk.org/svn/dahdi/linux-complete/tags/2.4.0+2.4.0

$ cd 2.4.0+2.4.0

$ make

$ sudo make install

$ sudo make config

How to Install It | 49