# Transparent Telephony - Part 2 - Installing Asterisk

By Randall Degges · February 28, 2010 · https://rdegges.com/2010/transparent-telephony-part-2-installing-asterisk/

> Part 2 of my Asterisk telephony series: install DAHDI, Libpri, Asterisk and Asterisk-Addons on CentOS with Digium's yum repos, or from source on Ubuntu.

![Telephone Sketch][]


**NOTE**: I wrote this article years ago, and its install steps no longer work. CentOS Linux has reached end of life, the Digium package repository shown here is gone, and Asterisk-Addons is now part of Asterisk itself. To install a current version of Asterisk, follow the [official install guide](https://docs.asterisk.org/Getting-Started/Installing-Asterisk/).

Welcome back to the Transparent Telephony series.  If you're new, you may
want to check out part 1 here:
[Transparent Telephony - Part 1 - An Introduction][].

This series is designed for technical people, programmers, and just general
enthusiasts who want to learn: how telephony works, how to setup your own phone
server (PBX), how to write telephony applications, and how to reduce your phone
expenses.  There are tons of neat things you can do with telephony knowledge,
so keep reading!

This article will walk you through installing [Asterisk][] on your [CentOS][]
or [Ubuntu][] server.  If you are going to install on a virtual machine to
follow along, I recommend using [VirtualBox][], as everything should work out
of the box.  Certain virtual machine programs like [Xen][] have kernel issues
which makes installing Asterisk difficult.  Also, never ever use Asterisk in
production on a virtual machine!  You'll have timing issues (this will be
explained later in the series).

Before we get started, go ahead and install either CentOS or Ubuntu on your
system.  Update everything to the latest version.  I'll be showing you how to
install the latest version of Asterisk stable, so we might as well update our
operating system and packages.


## Installing Dependencies

### CentOS

You can skip this step as [Digium][] provides yum repositories which will
automatically install the latest version of Asterisk for us as well as any
dependencies.


### Ubuntu

First of all, let's install the appropriate kernel sources.  We will need these
to build against.  To figure out what kernel version you're using, run the
`uname -a` command.

Next, you'll want to search for the appropriate kernel packages to install,
`apt-cache search 2.6.31` (where 2.6.31 is your kernel version).  Once you get
a list of packages, install the appropriate `linux-headers`, `linux-image`, and
`linux-source` packages that correspond to your kernel version.  For me this
was:

```console
$ apt-get install linux-headers-2.6.31-14-generic
$ apt-get install linux-image-2.6.31-14-generic
$ apt-get install linux-source-2.6.31
```

Now install the SSL libraries required for encryption.  We'll also install SSH
so that you can remotely administrate your server:

```console
$ apt-get install openssl libssl-dev ssh
```

Next we'll install all of the tools required to build Asterisk:

```console
$ apt-get install gcc
$ apt-get install g++
$ apt-get install make
$ apt-get install automake
$ apt-get install autoconf
$ apt-get install build-essential
$ apt-get install bison
$ apt-get install flex
$ apt-get install libtool
$ apt-get install libncurses5
$ apt-get install libncurses5-dev
$ apt-get install libgsm1
$ apt-get install libgsm1-dev
$ apt-get install libnewt-dev
$ apt-get install libnewt-pic
$ apt-get install curl
$ apt-get install libcurl3
$ apt-get install tclcurl
$ apt-get install libwww-dev
$ apt-get install mysql-common
$ apt-get install mysql-client
$ apt-get install libmysqlclient16
$ apt-get install libmysqlclient16-dev
$ apt-get install sox
$ apt-get install libsox-fmt-all
$ apt-get install madplay
$ apt-get install libxml2
$ apt-get install libxml2-dev
$ apt-get install doxygen
```

You may also want to install `ntp` as it's a safer alternative to `ntpdate`
which most system administrators use to adjust the system time.  DAHDI, the
Digium Asterisk Hardware Device Interface, is very picky about system time, and
has been known to crash servers which experience large time corrections.  `ntp`
will prevent this from happening as it will periodically adjust the time in
small increments which is much safer than performing a single large time
adjustment with `ntpdate`.

If you'd like to install `ntp`, just run: `apt-get install ntp`.


## Installing Asterisk

Now that we've got our dependencies worked out, it's time to actually install
Asterisk!  We'll install DAHDI, Asterisk, Asterisk Addons, and all of the
Asterisk default sound files.  We'll also ensure that Asterisk starts at boot,
and runs as a system service.


### CentOS

As a disclaimer, these instructions have been largely taken from Digium's
website.  They have excellent documentation for installing Asterisk using their
yum repositories which I will be mirroring here.

-   Download the `centos-asterisk.repo` file and copy it to
    `/etc/yum.repos.d/`.  Here is the repo file:

```ini
[asterisk-current]
name=CentOS-$releasever - Asterisk - Current
baseurl=http://packages.asterisk.org/centos/$releasever/current/$basearch/
enabled=1
gpgcheck=0
#gpgkey=http://packages.asterisk.org/RPM-GPG-KEY-Digium
```

-   Download the `centos-digium.repo` file and copy it to `/etc/yum.repos.d/`.
    Here is the repo file:

```ini
[digium-current]
name=CentOS-$releasever - Digium - Current
baseurl=http://packages.digium.com/centos/$releasever/current/$basearch/
enabled=1
gpgcheck=0
#gpgkey=http://packages.digium.com/RPM-GPG-KEY-Digium
```

-   Clear your current yum cache: `yum clean all`.

-   Install Asterisk and its dependencies:

```console
$ yum install asterisk16
$ yum install asterisk16-configs
$ yum install asterisk16-voicemail
$ yum install dahdi-linux
$ yum install dahdi-tools
$ yum install libpri
```

-   Make Asterisk and DAHDI start at boot.  Then reboot the server to make sure
    they both start up: `chkconfig dahdi on; chkconfig asterisk on; reboot;`.

Once the system comes back up, run the following command to make sure DAHDI and
Asterisk are working properly:
`service dahdi status; asterisk -rx 'core show version'`.

If all is working, you should see something similar to:

```console
### Span 1: DAHDI_DUMMY/1 "DAHDI_DUMMY/1 (source: Linux26) 1" (MASTER)
Asterisk 1.6.0.25 built by root @ localhost.localdomain on a i686 running Linux on 2010-02-26 20:30:00 UTC
```


## Ubuntu

To install Asterisk on Ubuntu, we need to compile it from source.

-   First of all, download all of the source files from
    [the Asterisk download page][].  Always download the latest release.  The
    files you will need are Asterisk, Asterisk-Addons, DAHDI Linux / DAHDI
    Tools, and Libpri.  The code below shows what Asterisk release I'll be
    downloading (current at the time of writing):

```console
$ wget http://downloads.asterisk.org/pub/telephony/asterisk/releases/asterisk-1.6.2.5.tar.gz
$ wget http://downloads.asterisk.org/pub/telephony/asterisk/asterisk-addons-1.6.2.0.tar.gz
$ wget http://downloads.asterisk.org/pub/telephony/dahdi-linux-complete/releases/dahdi-linux-complete-2.2.1+2.2.1.tar.gz
$ wget http://downloads.asterisk.org/pub/telephony/libpri/releases/libpri-1.4.10.2.tar.gz
```

-   Now, let's install DAHDI Linux / DAHDI Tools. Always install this before
    Asterisk:

```console
$ tar zxvf dahdi-linux-complete-2.2.1+2.2.1.tar.gz
$ cd dahdi-linux-complete-2.2.1+2.2.1
$ make
$ make install
$ make config
```

-   Now we'll install Libpri:

```console
$ tar zxvf libpri-1.4.10.2.tar.gz
$ cd libpri-1.4.10.2/
$ make
$ make install
```

-   Now that we've got both DAHDI and Libpri installed, let's install
    Asterisk:

```console
$ tar zxvf asterisk-1.6.2.5.tar.gz
$ cd asterisk-1.6.2.5/
$ ./configure
$ make
$ make install
$ make config
$ make samples
$ make progdocs
```

-   Finally, we'll install Asterisk-Addons which includes some useful
    functionality:

```console
$ tar zxvf asterisk-addons-1.6.2.0.tar.gz
$ cd asterisk-addons-1.6.2.0/
$ ./configure
$ make
$ make install
$ make samples
```

Now that we've got everything installed, go ahead and reboot the system to make
sure that everything starts up automatically on boot.  Once the system is back
up and running, run the following two commands:

```console
$ /etc/init.d/dahdi status
$ asterisk -rx 'core show version'
```

If all is working, you should see something similar to:

```console
### Span  1: DAHDI_DUMMY/1 "DAHDI_DUMMY/1 (source: HRtimer) 1" (MASTER)
Asterisk 1.6.2.5 built by root @ ubuntu on a i686 running Linux on 2010-02-28 22:30:53 UTC
```


## Conclusion

Now that you've got DAHDI, Libpri, Asterisk, and Asterisk-Addons installed,
your server is ready for production usage!

Our next article will cover configuring Asterisk and making calls to the
outside world.

If you're looking for some other great Asterisk documentation, you can't do any
better than [Asterisk: The Future of Telephony, 2nd Edition][].  It's the most
thorough book on Asterisk that you can find, and will teach you everything you
need to know to get started with Asterisk.


[Telephone Sketch]: telephone-sketch.png "Telephone Sketch"
  [Transparent Telephony - Part 1 - An Introduction]: /2009/transparent-telephony-part-1-an-introduction/ "Transparent Telephony - Part 1 - An Introduction"
  [Asterisk]: http://www.asterisk.org/ "Asterisk PBX"
  [CentOS]: http://centos.org/ "CentOS"
  [Ubuntu]: http://www.ubuntu.com/ "Ubuntu"
  [VirtualBox]: http://www.virtualbox.org/ "VirtualBox"
  [Xen]: http://xen.org/ "Xen"
  [Digium]: http://www.digium.com/en/ "Digium"
  [the Asterisk download page]: http://www.asterisk.org/downloads "Asterisk Download Page"
  [Asterisk: The Future of Telephony, 2nd Edition]: http://www.amazon.com/gp/product/0596510489/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=0596510489&linkCode=as2&tag=rdegges-20 "Asterisk: The Future of Telephony, 2nd Edition"