it's not your xbox don't break that!
what you might want to break is your router, before you go buy a new one (although you can fix it on some routers with port forwarding, i had to buy a new one...). Some of the routers ISPs provide are reallllllly terrible and have no idea how to connect an xbox to the internet.
one other thing it could be is your method of connecting. If you bridge from a laptop it can do some really screwy things. the best way to go is straight ethernet cord from the router or modem.