The Fabric of Network: Ethernet By: Mujtaba Faraz Baig Mirza

OBJECTIVE  Introduction to Ethernet  Evolution of Ethernet  Introduction to CSMA/CD  Methods of Communication  A brief explanation of Ethernet addressing  A view of network cards  Understanding Ethernet cabling  The two types of Ethernet cables

 The term Ethernet refers to a family of standards that together define the physical and data-link layers of the worlds most popular type of LAN  Initially the company Xerox created the original Ethernet standard, later on the Institute of Electrical and Electronics Engineers (IEEE) has defined many Ethernet standards since it took over the LAN standardization process in early 1980s Introduction to Ethernet

 Ethernet refers to the bottom two layers of the OSI model i.e. Layer1 & Layer2  At the data link layer Ethernet is further divided into two sub layers: 1) Media access control (MAC) layer 2)Logical Link Control (LLC) layer

Methods of Communication  Unicast : One to one  Broadcast : One to All  Multicast : One to Many

Ethernet Addressing  IEEE calls it as MAC addressing  Each address is 6 bytes long (48 bits) written in hex decimal format with periods separating each set of 4 hex digits Ex: c  To ensure a unique MAC address, IEEE assigns an unique code to the manufacturer of the Ethernet cards,this code is known as Organizational unique Identifier (OUI).  The OUI is the first half (24 bits) of the MAC address. The second half is a number that is never assigned by the manufacturer to any other card.

A view of Network Cards

Ethernet Cables Telecommunication Industry Association (TIA) and Electronics Industry Alliance (EIA)defines standards for UTP cables like color coding on the cable

Two Types of Ethernet Cables

Ethernet Connection Rules