Adding extra modem
My friend is getting a new computer and he only has 1 modem that has only one Ethernet port output that is already being used. I suggested that he buy a router and run a cable through the stairs (underneath) to his room. This would cost approximately $30. Then I suggested he buys a wireless router (Netgear) and a wireless adapter (Gigabyte). This would cost $65. But now, he is wondering if he can just hook up a cable from the wall jack at his room, to another modem, and then to the computer. The implication with this is that it might not work/cost more. He currently has SBC Global (AT&T I believe). Will it add to his monthly bill and is it actually possible to do this?