Originally Posted by hobbyguy
the other end into a at&t modem on local Ethernet plug 1 and I also try the broadband but nothing happen
Is this just a basic DSL modem or does it come with built-in router functionality as well? All of the basic modems AT&T gives out in my area require a dial-up type of dialer to authenticate you before you can use the internet. If there is a router built in, or you have this connected to a router that's in between you and the modem you wouldn't need that, but it sounds like you are missing the authentication utility.