1. Follow the step by step instructions contained in this link to find your VoIP IP address enter this into the address bar of a web browser to take you into your Gigaset web interface settings:
By doing the above you will remove the flashing alert notifications for missed calls and voicemail messages.
2. Update the firmware on your phones that are affected – please click here to see the instructions.
3. After the firmware has been updated please then switch off your base station and turn back on again. Make sure that you actually remove the ethernet cable from the base station and then plug this back in again.
This should then resolve the issue for you, meaning that your phone will no longer show that you have voicemail messages and will stop beeping.
Please note: that by updating the firmware on your phone you may lose any configuration settings that have already been set up on your phone such as hunt group configurations/ring tones etc which may need to be re-applied.