How to Install Asterisk in Ubuntu 20.04

Asterisk, a popular open-source platform for developing communication applications and is used by a lot of people. Voicemail, On hold music, conference calling, call recording, interactive voice response, and much more are the features of Asterisk platform. In this tutorial we will learn how to install and setup Asterisk in Ubntu 20.04

This setup is tested on Google Compute Engine VM Instance running Ubuntu 20.04 LTS.

This setup will work fine for any virtual machine on AWS EC2 Instance or DigitalOcean or any other cloud hosting servers or VPS or Dedicated.

Prerequisites

1. A running Compute Engine, see the Setting up Compute Engine Instance with Ubuntu 20.04.
2. Basic knowledge and understanding about Linux commands
3. Install the necessary packages to download and build Asterisk

sudo apt update
sudo apt install wget build-essential git autoconf subversion pkg-config libtool

Installing DAHDI and LibPRI

DAHDI drivers and utilities are used to communicate with telephones and the LibPRI library is used to communicate with ISDN connections.

Now let us download and install DAHDI in /usr/src directory

cd /usr/src/
sudo git clone -b next git://git.asterisk.org/dahdi/linux dahdi-linuxcd dahdi-linux
sudo make
sudo make install

cd /usr/src/
sudo git clone -b next git://git.asterisk.org/dahdi/tools dahdi-tools
cd dahdi-tools
sudo autoreconf -i
sudo ./configure
sudo make install
sudo make install-config
sudo dahdi_genconf modules

Now let us build LibPRI in /usr/src directory

cd /usr/src/
sudo git clone https://gerrit.asterisk.org/libpri libpri
cd libpri
sudo make
sudo make install

Install Asterisk

Install Asterisk18.x source in the /usr/src directory

cd /usr/src/
sudo git clone -b 18 https://gerrit.asterisk.org/asterisk asterisk-18

Switch to Asterisk directory

cd asterisk-18/

Download MP3 sources to build the MP3 module

sudo contrib/scripts/get_mp3_source.sh

Now run install_prereq to install necessary dependencies

sudo contrib/scripts/install_prereq install

Check if we have all the requied dependencies using the configure script

sudo ./configure

Now open menuselect and choose the format_mp3 option

sudo make menuselect

You will see the menuselect window, choose the format_mp3 option and Save & Exit
Now start the compilation process, modify the -j flag with the number of cores in your processor. This will take some time depending on your system capacity

Now let’s install Asterisk and its modules

sudo make install

Installing Sample Files

Install sample configuration files for Asterisk

sudo make samples

Now install the initialization script to start Asterisk when your server starts

sudo make config

install logrotate to rotate log files and save disk space

sudo make install-logrotate

Now run ldconfig to update shared libraries cache

sudo ldconfig

Create Asterisk User

For security reasons we will create a new system user asterisk and configure Asterisk to run as new user

sudo adduser --system --group --home /var/lib/asterisk --no-create-home --gecos "Asterisk PBX" asterisk

Open the /etc/default/asterisk file and uncomment the following lines

AST_USER="asterisk"
AST_GROUP="asterisk"

Add the asterisk user to the dialout and audio groups

sudo usermod -a -G dialout,audio asterisk

Now we need to update the permissions of all asterisk files and directories so that new user can access those files

sudo chown -R asterisk: /var/{lib,log,run,spool}/asterisk /usr/lib/asterisk /etc/asterisk
sudo chmod -R 750 /var/{lib,log,run,spool}/asterisk /usr/lib/asterisk /etc/asterisk

Start Asterisk

Now we can start the Asterisk service

sudo systemctl start asterisk

We can verify Asterisk is running by connecting to the Asterisk CLI

sudo asterisk -vvvr

You must see something like this

Connected to Asterisk 18.1.1 currently running on asterisk (pid = 104513)
asterisk*CLI>

Now setup Asterisk service to start on boot

sudo systemctl enable asterisk

Configure Firewall

Now let us setup firewall to secure our server. Open UDP port 5060

sudo ufw allow 5060/udp

Feel free to adjust the firewall according to your needs.

Conclusion

Now you have learned how to install Asterisk in Ubuntu 20.04

Thank you very much for your time. If you face any problem or if you have any feedback, please leave a comment below.