T48G - busy tone for a second incomming call

[complex1]

Hi,

I do not have a FritzBox or familiar with it, so I have register my T48G directly to my VoIP Provider.
Before I did the test I set “Call Waiting” to “Disabled”
All other settings in the Features tab are untouched and remain the same.
Then I make a call to the T48G and accept it.
Then I make a second call to the T48G and get/hear a busy sound.
So if you set “Call Waiting” to “Disabled” it should also work for you.
If not, then I think you FritzBox is doing something what you don’t want it to do.