Disable Call Waiting on Gigaset N510 / S650H / R650H
To disable call waiting on a handset connected to the Gigaset N510, follow the steps below on your handset:
Press the ‘Menu’ button on your handset.
Navigate to ‘Select Services’ / ‘Network Services’, then press OK.
Select ‘Call Waiting’.
Change the status to ‘On’ or ‘Off’, then press ‘Send’.