How to Block other users from accessing the internet using your Modem

United States
@3oooof (171)
May 16, 2010 5:08pm CST
Hello everyone , i'm using sagem modem to access the internet and my little brother using the same modem , the problem is he use the internet to download movies and game and when i try to play games online the game is lagging , i want to find a way to block his Ip from accessing the internet is there any way to do this ? ps:- my modem is sagem 2006