3CX created an ISO of Debian Linux that is dedicated to 3CX. It is strongly recommended that you do not change the instances configuration or install any other packages as 3CX will then be prevented from upgrading your instance of Debian to a new version and it will not be supported by 3CX.

Use of the Debian Linux ISO allows for faster installation, and easier management that can be done from within the 3CX web management console.

System, Network and Firewall Requirements


As a general rule, your Linux machine or VM will need at least:

  • 1 CPU core
  • 1 GB RAM

Note: It will run on a Google Cloud f1 micro instance with 612mb RAM for very small installs.

Allocating additional CPU time and RAM should be based on the following factors:

  • Amount of active users
  • Usual amount of simultaneous calls
  • Call recording – this places significant strain on the system

Network & Firewall

  • If installing on the local LAN:

Must be properly configured using a RFC 1918 private network
(i.e. IP / range)

  • Latest version of Firefox, Chrome or Edge
  • A constant internet connection to activation.3cx.com on port 443
  • On-demand HTTPs connection to downloads.3cx.com/*

Supported VM Platforms

  • VMware ESX 5.X and above
  • Microsoft HyperV 2008 R2 and above
  • KVM
  • Citrix XenSerer 7.0 and above

Supported Mini PCs

  • Gigbyte (Recommended for between 4 – 8  simultaneous calls)
  • Intel NUC (Recommended for between 4 – 32 simultaneous calls depending on model)
  • Zotac (Recommended for between 4 – 8 simultaneous calls)
  • Shuttle

[3cx-clicktotalk id="29505" title="AatroxComms"]

Debian for 3CX Installation

1. Download the Debian for 3CX ISO

2. If using a hypervisor/ virtualised OS:

  • Ensure CD drive is set to connect on startup
  • Set the CD option to boot from the ISO

3. If using a Mini PC:

  • Create a bootable image
  • Plug into a USB port
  • Set the BIOS to boot from the USB drive
4. Boot system with the ISO & select “Install” from the main boot screen.
3CX Linux boot screen
5. Enter a hostname for the computer so that it is easily identifiable on your network.

  • Note: if you need to configure a static IP address, press “ESC” when asked for the hostname and you will return to the hostname configuration screen once the IP address has been set.
  • If you don’t want to set a static IP address, enter a hostname and go to step 7.
3CX Linux hostname
6. Select “Configure Network Manually” to get a static IP address.
3CX Linux configure network
7. Enter a domain name.

  • Note: If this is a network, use the same domain you use on other computers in the network.
3CX Linux domain name
8. Select your language
3CX Linux language
9. Select your location, this will update the system locale
3CX Linux location
10. Specify the root password, you will also be prompted to re-enter to verify.
3CX Linux root password
11. Select Timezone
3CX Linux timezone
12. Partition your disk with the “Guided – use entire disk” option.
3CX Linux guided partition
13. Confirm your disk. Note that all data on this disk will be erased.
3CX Linux confirmation
14. Select “All files in one partition”
3CX Linux single partition
15. Select “Finish partitioning” and Debian for 3CX will be installed.
3CX Linux finish partition
16. Confirm changes to disk by selecting “Yes”.

This may take approximately 10 – 20 minutes depending on the speed of your machine.

After this, your machine will be restarted and 3CX will be installed automatically.

3CX Linux partition confirmation
17. When the installation is complete, you will be prompted to select how you would like to configure 3CX –

(1) Web Browser
(2) Command Line

Select option 1 and use your browser to go to https://ip-of-machine:5015

3CX Linux server configuration
18. 3CX will now take you through the configuration wizard.

3CX will detect your IP, ask whether you are behind a NAT and confirm options with you.

You will be asked to choose a subdomain and admin credentials for your PBX.

A summary page will be displayed with information to login to your PBX.

Removing Debian for 3CX

There are two options should you want to uninstall 3CX

  1. apt-get remove 3cxpbx
    • Uninstalls 3CX without removing data files, database and recordings. This option is useful if you would like to reinstall 3CX at another time.
  2. apt-get remove –purge 3cxpbx
    • Completely remove 3CX and all associated files.

Manual Installation


This article serves as a guide for manual installation of 3CX on a Linux system. Debian installations using the 3CX ISO have 3CX automatically installed, however due to a number of reasons this is not always accessible. If this is the case, this guide will assist you in installing 3CX on Linux manually.

Note: The 3CX client is currently only available on Linux Debian 8 and 9 and will not work on different versions of Debian or other Linux distributions.



  • Linux Debian 8 (kernel 3.16)
  • Linux Debian 9 (kernel 4.9)
  • Ensure you have SSH access and you are able to connect
  • Do not install any other software on this Linux instance – ensure it is dedicated to 3CX.

Installing 3CX

Connect via SSH and enter the following commands:

wget -O- https://downloads-global.3cx.com/downloads/3cxpbx/public.key | apt-key add –

echo “deb https://downloads-global.3cx.com/downloads/debian stretch main” | tee /etc/apt/sources.list.d/3cxpbx.list

apt-get update

apt-get install 3cxpbx

apt-get install net-tools

Installation with then be completed and you may proceed to the first time configuration using the 3CX Configuration Tool