Hello,
After a lot of research, I found a solution to get access which work for me (I have a thomson SpeedTouch 706 but probably it will work for other routers): I have assigned the public IP address to MBL. And now it works 
:smileyvery-happy::smileyvery-happy::smileyvery-happy:
You can follow the path Home>Home Network>Devices>Assign the public IP address of a connection to a device.
I do not know yet if this is the best solution, if anyone have other solution, please suggest and I will try…
From my experience, I would be very surprised that lot of people will be able to setup their router themself !
So, if you succeed using this method please take a few time to register and leave your experience.
Thank you to all followers.