How Ethernet Works
Any network design must address a number of key elements: the type of media to use, how to send data across the wire, how to identify the sending and receiving computers, and how to determine which computer should use the shared cable next.
Chapter 2 discussed the physical cabling used in Ethernet. Ethernet networks can use coaxial cable, unshielded twisted-pair (UTP), shielded twisted-pair (STP), or fiber. Regardless of the physical cabling used, the data moves across the wire in essentially the same way. Any network requires a method for determining which device uses the network media at a given time.
Ethernet networks use carrier sense, multiple access/collision detection (CSMA/CD) to determine which computer ...