I can't connect to my game

I was playing with a friend and at 2 or 3 min my game crash and a message tell me that i had not connexion but i had at this moment connexion because i could go on internet and watch videos on youtube, i decide to restart my box after 3 try to reconnext to my game i restart my game and league tell me that i had still no connexion i don't know what can i do...