Physical Characteristics of a Network
There are three primary cabling media that can be used with a LAN at the physical layer; Twisted pair cable, Coaxial cable and Fiber-optic cable.
Twisted pair cable consists of two insulated strands of copper wire twisted together.
Coaxial cable is a conducting center wire surrounded by an insulating layer, a layer of wire mesh and a non-conducting outer layer.
Two popular types of Coaxial cable are Thinnet and Thicknet. Optical fibers are used to carry digital data signals in the form of modulated pulses of light.
Encoded signals can be transmitted over cable two ways, broadband and Baseband transmission.
Broadband transmissions use analog signaling and Baseband transmissions use digital signaling.
Three widely used LAN topologies are bus, star and ring topologies.
A bus topology connects each computer to a single cable. In a star topology, each station is connected to a special unit called a hub.
On a ring network, stations are situated on a continuous network loop.