A network switching apparatus for supplying power to network communication equipment through a twisted pair line comprising a power control circuit having a plurality of sockets, each socket connected with a RJ-45 connector so as to electrically connect the switching apparatus to a corresponding socket of the communication equipment through the twisted pair line of RJ-45 connector, and having the ability to identify, in accordance with specifications stipulated in IEEE 802.3af, whether the communication equipment has the capability of receiving power from each socket through the twisted pair line prior to supplying power to the communication equipment.