Bad Quality of Video

I see my own video cristalclear.
The others see mee in a bad quality.
I work with a Lenovo T530
My Modem is a fritzbox 6430 Cable
The Internet ha 10MB download (I see the others perfect) and 3MB upload.
On wich screw i have to move for a better quality?

is this the official deployment ( or a custom one?