The easiest way to set up Fanvil IP phones for use 3CX Phone System is to use the built-in plug and play provisioning functionality that’s provided for you inside the 3CX Management Console. By auto provisioning your Fanvil phone configures itself by retrieving a 3CX-generated phone configuration file. If you prefer configuring your phone using the DHCP and option 66, check out this DHCP Option 66 Configuration guide.