I have AT&T DSL for which they furnished a moden/router combination. I have tried to connect the deco M5, all units are green lights but problems: If I set my android phone to Deco network, I get msg,

I just received this unit and tried to install. During installation I was asked for my PPoE user name and password. Since I have no idea what these are, I'm stuck. Help!! I have ATT&T DSL which comes