The first step in tying 3CX and Openfire together will be adding some plugin to the Openfire server, so let's log in to the Administrator Console.
For the plugin installation, the Openfire server needs to have Internet access.
Now click on Plugins | Available Plugins. Then install the Client Control and SIP Phone Plugin, as shown in the following screenshot:
Let's verify that the plugin is installed by clicking on Plugins:
Now, we will create the mappings between Openfire and 3CX by clicking on Server | Phone | SIP ...