I am in the process of installing a new network router (N,300MBPS). During the installation process , it asks me to put in my (AT&T DSL) ISP ID and Password, I don't remember them any more since that was installed two years ago. I can call AT&T to find out, but just wonder why do I need ISP ID and password in the router ? Can someone tell me how the router work, If I put in a wrong one in , is it going to work ? Thanks.