• Introduction
  • Step 1: Check System Requirements
  • Supported VM Platforms
  • Supported Mini PCs
  • Network, Firewall & Other Requirements
  • Step 2: Install Debian for 3CX
  • See Also


3CX created a Debian Linux ISO (get ISO here) to make installation faster and management easier. The OS management can be done from within the 3CX Management Console. To be able to request support, you must dedicate your Debian Linux instance to 3CX. 

  • Do not install other packages or change the configuration.
  • Do not  install system updates via the command line! This is done by the 3CX system via updates after they have been tested!
  • Any changes to the system will render your installation unsupported!

Step 1: Check System Requirements

Υour machine or VM needs at least one (1) CPU core and one (1) GB of RAM. Review the suggested hardware specifications to allocate additional CPU time and RAM resources based on:

  • Number of simultaneous calls the system handles.
  • Number of active users – 100 Web Client active sessions is more demanding than 100 occasional calls via IP phones.
  • Call recording use – stresses the system for audio mixing and file storage.

Supported VM Platforms

3CX is tested and supported to run as a Virtual Machine on these hypervisor platforms:

  • VMware vSphere Hypervisor (ESXi) 6.5u1 and above, with VMWare Tools package installed.
  • Microsoft Hyper-V Server 2012 R2 and above capable of running Win10, Server 2016 and above – see our Hyper-V Page for required settings.
  • KVM 2.8 and up
  • Citrix XenServer 7.0 and above.

Avoid using 3CX on converted VMs (P2V) due to possible timing issues, causing the guest OS not to sync with the hypervisor’s timer.

Supported Mini PCs

3CX Phone System has been tested on popular MiniPC models such as Intel NUCShuttle XPC NanoGigabyte BRIX and Zotac Zbox.

Network, Firewall & Other Requirements

  • LAN installs are supported on properly configured RFC 1918 private networks, i.e. / range IP range.
  • The PBX needs to be configured with a dedicated public IP.
  • Installing 3CX on a machine behind a NAT device, requires port forwarding. See the Firewall & Router Configuration Guide.

Step 2: Install Debian for 3CX

To install Debian for 3CX:

  1. Register at 3cx.com to get a customer account, the download URL for the Debian 9 for 3CX ISO and the license key for your install.
  2. If you are using a hypervisor/virtualized OS set the CD option to boot from the ISO and ensure the CD drive is set to connect on startup. If you are installing on a mini PC, then create a bootable image, plug it into one of the available Mini PC’s USB ports, set the BIOS to boot from the USB drive to start the installation.
  3. Boot your system with the downloaded 3CX ISO, select “Install” from the main boot screen and press the <Enter> key.
  4. Important: You need to configure a static IP address for the 3CX host machine. Select <Go Back> or press the ‘ESC’ key when asked for the hostname to first set the IP address of the system and then configure the hostname. The system’s IP address affects the running PBX services, connected clients and IP phones. To change the IP address on a running 3CX system, you need to reboot the machine and then re-provision the connected apps and IP phones. If you don’t want to set a static IP address, proceed to Step 6.
  1. Select “Configure Network Manually” and press the <Enter> key to set the system’s static IP address. Select <Continue> to enter the network netmask and select <Continue>. Then, enter the network default gateway IP address and select <Continue>. Finally, enter the name server(s) IP address(es) and select <Continue>.
  2. Enter a hostname for the computer so you can easily identify it on your network, using the characters ‘a’ to ‘z’, numbers ‘0’ to ‘9’ and the ‘-‘ character.
  3. Enter a domain name – use the same domain you used on other computers in the network, e.g. mycompany.com. Select <Continue> to proceed.
  4. Select the default system language and press the <Enter> key.
  5. Select your geographical location from the location menu and press the <Enter> key to proceed.
  6. Specify the root account password for the machine and select <Continue> to re-enter the password for verification purposes. Finally, select <Continue> to proceed.

Note: Set a strong password for theroot user, as this account has no restrictions!

  1. Select the system timezone and press the <Enter> key to proceed.
  1. Partition your disk, selecting “Guided – use entire disk”. Press the <Enter> key to proceed.
  2. Confirm your disk selection by pressing the <Enter> key.

Note: If you are installing on a bare metal machine, all data on your disk will be erased!

  1. Select the “All files in one partition” partitioning scheme and press the <Enter> key to proceed.
  2. Select “Finish partitioning and write changes to disk” and press the <Enter> key to proceed to the 3CX Debian installation.
  3. Select ‘Yes’ and press the <Enter> key to confirm writing changes to the disk. The install process can take about 5-20 minutes, depending on your machine’s performance. When the Debian installer finishes, the machine is rebooted and the 3CX installation starts automatically.
  4. Now select the 3CX package to install on the “3CX Update Channel” screen. Select “3CX Stable”. Select <OK> to agree to the 3CX License Agreement on the “Configuring unattended-upgrades” screen.
  1. After the 3CX install finishes and the machine is rebooted, run the 3CX configuration wizard via:
  2. (1) a web browser to open http://<ip of machine>:5015.
  3. (2) the command line. 
  4. Visit this guide for step by step instructions on running the first time configuration wizard.

Source : – https://www.3cx.com/docs/manual/installing-debian-linux-pbx/