layer 1 (l1) of the (osi) seven-layer model:  the physical layer defines hardware connections and turns binary into physical pulses (electrical or light). cables operate at the physical layer.
layer 1 (l1) of the (osi) seven-layer model:  the physical layer defines hardware connections and turns binary into physical pulses (electrical or light). cables operate at the physical layer.
defines the physical characteristics of the transmission medium (connectors, pins, electrical currents, encoding, light modulation, etc) rj-45, ethernet (ieee 802.3) lan hub, lan repeater, cables