Section - Installation
2. Enable or disable this function and press Select.
It allows you to disable the Call Waiting tone if you don't want the tone to break into the active call you are engaged in.
Please select 04.Call Function -> 05.C.W. Tone Notify.
1. Select C.W. Tone Notify and press Select.
2. Enable or disable this function and press Select.
D-Link DPH-18MS User Manual
Call Waiting Tone Notification