Ps3 hook up to modem help me

Hello, i cant seem to hook up my ps3 to my modem i dont have a router only a modem. my modem is a motorola surfboard modle SBV5222 i have a username and password to get on it and it still fails to connect. i tried to set it up with out the PPPoE setting and i use my ip adress and it fails at internet connection i would like to not have to buy a router can anyone help
i can go wireless by using my someone elses but i want to use mine my psn name is Rudyheartless till i get this fix im using wireless thats not mine so add me if u can help or email me
thank you