A network device relating to a digital subscriber line (DSL) such as an asymmetrical DSL (ADSL) or a very high bit rate DSL (VDSL) is provided. In the present invention, the capacitors equipped into the network device are separated and grouped into two independent groups. When the network device runs out of power, the energy of one of the two independent groups is provided for generating the dying gasp signal, and the energy of the other of the two independent groups is provided for amplifying and transmitting the dying gasp signal to a Central Office (CO). Accordingly, the CO can be accurately known whether the network device runs out of power or not, and the respective capacitances of the two independent groups can be significantly reduced so as to reduce the cost of the network device.