How to Configure Many Extension Ringing

Select the Add button on the Many Extensions Ringing Settings page to display the Add Caller for Extension page in the browser window.
Fill in the optional Description about the caller party.
Specify the new caller address with its extension number, its user name or host address in the text field Caller Address.
Click Save to complete the operation.
Click on this new caller address to display the Ringing Extensions list.
Select one or more extensions from the list and press Enable.
Go back to the page Many Extensions Ringing Settings with Back button.
To complete the many extensions ringing setup, enable the function with the checkbox Use Many Extensions Ringing and finish with Save.