What is Ethernet?
The Ethernet is the most widely used Local Area Network (LAN) which uses a cable type known as Ether. The Ethernet indicates how signals move across wires. Hubs, routers and Computers communicate using signals within a given network.
The advantages of Ethernet are
- Simplicity of installation
Therefore learning about Ethernet which offers such advantages is crucial for anyone who wants to be a network administrator.
Ethernet is a data transmission protocol defined by the IEEE 802.3 standard. It replaces the token ring network topology that was commonly used in the 1980s. in a Token Ring network, a logically organized token is passed from one computer to another for data transmission. The other computers in a network cannot send or receive any data until the token is free.
Even though this token passing mechanism prevents the collision in a network, it causes a lot of delay in data transmission.
Ethernet, on the other hand, is developed to provide simultaneous data transmission with the high-speed data rate, it supports TCP/IP which in turn provides both LAN and internet.
Ethernet Networking in the Physical Layer.
The ‘Hub’ is a commonly used device in the physical layer. Ethernet hub has two limited functions Namely
- Half duplex
- Shared Bandwidth
Though the Ethernet is developed for simultaneous data transmission, there is a greater possibility of a collision in the network since the nature of the hub is half-duplex with shared bandwidth.
Hubs simply send the received data in all connected ports except the port it received from, which leads to the broadcast. Ports in the hubs share bandwidth.
Example – Assume you have a 10 Mbps speed hub with 4 ports and all ports share equal bandwidth (2.5 Mbps). If a collision occurs in one port, all the other ports will also be affected by this collision.
A collision occurs in a ‘Hub’ environment when two or more hosts try to send or receive data simultaneously. If a collision occurs in one port, it will affect the entire hub because the same media (Bandwidth) is shared across the hub.
This makes it a ‘one Collision Domain’
In a Hub network, when a host tries to communicate to another host, the hub will broadcast to all the ports that lead to the broadcast domain. Irrespective of the number of connected hosts, all hosts and devices including switches and bridges will come under one single broadcast.