3CX V18 Pre-Installation Requirements

It is recommended that no other programs other than 3CX IP Switchboard software be installed on the operating system you will install.

  • It is recommended that you have all the updates for your operating system installed.
  • Do not install VPN software on your 3CX server.
  • Make sure all power saving options are disabled for your System and Network adapters.
  • To increase the performance of Windows operating systems, check the Adjust for best performance option in System Properties\Advanced\Performance Options\Visual Effects tab and Background services as Processor timing in System Properties\Advanced\Performance Options\Advanced tab.
  • Use physical network cards for server networking.
  • Disable the Bluetooth and Wifi adapters in your operating system.
  • 3CX PBX should not be installed on a host with a DNS or DHCP server.
  • Server ip address must be static.
  • The IP address to be defined to the server must be configured in accordance with the scope of RFC 1918 private networks. 
    •  -  ( / 8)
    • - ( / 12)
    • - ( / 16) 
  • In cases where more than one network card will be used on the server, Gateway definition should not be made on your other network cards other than your network card that will go to the internet, and the necessary routings should be made from the route table.
  • It is recommended to temporarily disable installed Antivirus programs during installation, and add the following directories to the not to be scanned area after the installation is complete.
    • C:\Program Files\3CX Phone System\*
    • C:\ProgramData\3CX\*


Changing the IP address defined on your network card after the installation of the 3CX IP Switchboard System will result in unstable operation of the system. In cases where IP address change is required, the backup file of the system must be taken and the server must be re-established after a new IP address is defined.