adsl filter

My phone line is connected into the phone port in the hall way... from which i have a line which runs into my bedroom with a box tht says phone and adsl on it... its a large box like you would plug your house phone into... however everytime my grans phone rings, my internet gets disconnected.... i have put a adsl filter onto the line in the hallway which only has my internet line pluged into it... the problem still happens =/ i dont know what to do

 

well if you call your internet company they will fix the issue