Newer version of firmware on the Grandstream executive handsets use a default ringtone 'You have a call from xxx' where xxx in the CLI of the inbound number.

We're often asked to remove this and the best way to make a permanent solution with 3CX is this:

Open the 3CX Windows Management Console and log on

Select Settings->Templates

Select the handset make and model in the Template drop down

Search for the following p values in the template and comment them out by adding a # to the start of the line

P1488=

P1489=

P1490=

P1491=

P1492=

P1493=

Then save the template

Now go to Extensions and open the extension settings. Click OK to regenerate a new configuration file for the handset.

Re-provision the handset from the 3CX console or the handset. When it restarts it will download the new configuration file with the modified ringtone settings.