I think there is (unfortunately for you) no way to enhance the ping, sorry. I suppose pinging via the FBF is slower (higher time count) because the FBF is just doing its routing job slower than your Alcatel router.
I can translate the menu items you have to click...
It should be Internet->DSL-Einstellungen->DSL-Filter für DSL-Modem aktivieren
This is without guarantee as my FBF is just the one without a DSL-modem, so I can't tell for sure.