How to connect Xbox Live To a Motorola Surfboard Modem...?

Ok...
I have a Motorola Surfboard Modem...
On the back of the modem, there's a ethernet cord on that's attached to the modem that's goin my desktop.
Then its the cabel cord (on the back of the modem)
& the power cord to the modem (on the back of the modem)

Now here's the problem... I DONT KNOW HOW TO CONNECT XBOX LIVE TO THE MODEM...

Do I: Take the ethernet cord from the modem & unplug it from the modem & my desktop. Then connect the XBOX ethernet cord to the back of the modem..?

Or...

Do I: Unplug the ethernet cord from the modem thats on the back of my desktop, then connect the XBOX ethernet cord to my desktop..??

I SERIOUSLY DON'T KNO WAT TO DO...
I NEED HELP FOR ANYBODY...
PLZ SOMEBODY TELL ME WHAT TO DO (STEP BY STEP)
ANYBODY....???

look at ur internet protocol its probally 4222 4221

what kind of answer is that? that didn't explain anything

ok look you cut the power to your modem then unplug the ethernet cord then plug your 360 ethernet cord into it turn the modem back on after all the lights come back on turn your 360 on and go to test conection and that should get you on live

dude my modem has only 2 slots does tht mean i wont be able to play on my computer at the ss=ae time

you were trying to use both at the same time? Modems are generally meant to connect to one other device, if you want to split connections, you need either a hub or a router.

my modem only has 1 ethernet port in the bak so i unplug it and plug in the xbox cable

plz help send me a message at [email protected] or if you hav a youtube at acdcrocks2000

what Ive done is I used the usb that came with the modem and use that to connect to the internet, and then used my ethernet cord plugged it into the computers ethernet port ; it worked for me. Or sameway, but instead connect the ethernet port into the modem and used the usb (that came with the modem ) as for your internet connection.
(only if you want to connect it to the modem, with this connection this would create an open Nat, which means connect to more game lobbies and reduce lag)

In my opinion I prefer the first option.