Basics of Ethernet

If you have to communicate with a friend, you use a local dialect or the English language to convey your message. The language you use has certain words, expressions or your own set of jargons that can be understood and used by your group. Similarly, computers on a local network have a standard set of communication 'words' or 'expressions' and tools that foster exchange of information. This standard is in use for many local area applications worldwide which we refer to as Ethernet protocol. It was originally developed by Xerox PARC (Palo Alto Research Center) in 1972. Later on, it was jointly developed by Digital Equipment Corporation, Intel corporation and Xerox corporation in 1980.

An Overview
An Ethernet network comprises of more than 1000 nodes, hubs, switches, bridges, routers, network interface cards and servers and many interconnecting cables. It was originally developed as a broadcast medium using coaxial cables. It was standardized with a new set of parameters enabling a faster, efficient and a widely accepted format. It is incorporated in the IEEE standard of networking protocol, which defines the various rules for a local area connection. There are several standard layers defined for a communication process. The basic layer of this process is the physical layer which deals with the actual connectivity between two communicating interfaces. An Ethernet standard is a set of all the rules and the physical devices comprising a physical layer of a protocol. Following are the various components of Ethernet.

Ethernet cable: It can be simply called as a wire which carries electrical signals from one computer to the other. These cables are classified into different categories depending on the type of application. Certain categories of cables and their usage are Category 3 or Cat 3 cable- It is used for a 10Mb speed Ethernet and voice transfer. Cat 5 cable- This is used for either 10 or 100 Mb Ethernet. Another version 5E is used for gigabit Ethernet which is faster and reduces cross-talk. It can handle speeds of 10/100/1000 Mb. Cat 6 cable- This is a slightly advanced version of 5E and works for 10/100/1000 Mb . Cat7 cable– Also called as the Class F cable, it is the latest and a fully shielded cable used for technical applications.
The most commonly used is the 5E cable.

Hubs: It is the intermediate connecting mechanism that connects two or more stations (computers, printers and so on). It has multiple terminals that carry cables in and out to various destinations. A hub can only work in linking just one computer to the other, at a time. In case of multiple access demand or if several computers are sending or receiving messages together to a single system, there is a 'collision' of signals. Although, a hub can detect such collisions, it cannot pass information simultaneously to multiple ports. It can send data to different ports at a time but cannot
receive data from different ports.

Switches: A switch is a scaled up version of a hub. It divides the given LAN into different segments and streamlines the flow in and out of different ports. In short, it allows signals from multiple ports and transfers it to another set of ports without interference or collisions.

Router: A router performs the functions of a hub and a switch along with additionally providing inter connectivity between two sub-networks, a network and a local station or firewall for securing LAN. It acts as a gateway for communication between two networks or a network and a single domain.

Ethernet card: It is also called as a network adapter that is used to handle the network traffic flow in and out of a computer. It controls all the aspects of computer networking with external mediums.

All these devices are a part of the larger functioning protocol called Ethernet. It lays down the framework of all networking which is carried out with the help of above devices. Ethernet has brought about a streamlining and standardization of global communication.