Call waiting

[Android Central Question]

when i call someone and he is on call no notification for me that the other person is on call

 

[ManiacJoe]

That would be normal.
The call waiting notification goes to the receiver so that he can choose to switch calls if desired. If he chooses not to switch, the second call goes to voicemail.
Without the call waiting system, the second call would go immediately to voicemail.