That's a telephone line. Go to the water station and open it The deposit is 200 yuan. I will give you a cat. If you use it alone, you don't need to buy a network cable. He will give you one when he comes to help you install it. If you use it together in the dormitory, you can buy a router. We are now in the new campus, using a wireless router. Some people in the old campus also use wireless routers, which is not bad. But at school, you can only run Tietong's network, because their dormitory phone is Tietong.