Ethernet
Ethernet is a network technology especially for local area networks. It is based on data frames. In OSI model an Ethernet operates on physical and data link layer. At physical layer it controls physical issues such as signals and wires. At data link layer it defines protocol (CSMA / CD) and frame formats for media access control (MAC). On IEEE bases Ethernet is standardized as IEEE 802.3. Since 1990, Ethernet standard has replaced other LAN standards including Token Ring.
Ethernet
Ethernet Protocol
Ethernet protocol is known as carrier sense multiple access with collision detection. This protocol defines the rules that how the computers share the transmission channel. It is based on simple algorithm whose simplest form is defined below:
- If medium is idle transmit, else go to step 2
- If the medium is busy, listen for idle, and then transmit
- If collision detected, jam then cease transmission
- Wait random amount of time, back off, and go to step 1.
Ethernet works with twisted pair and optical fiber cables. It provides three types of data rates as: 1000Mbps is Gigabit Ethernet that is now has reached to 10-gigabit ether net. Also provides low data rates as: 10 Mbps (10Base-T Ethernet) and 100 Mbps (Fast Ethernet).
10GB Ethernet
A 10Gb Ethernet is the fastest Ethernet so far. It provides a very high speed and supports large capacity switches. It allows the NSPs – network service provides and ISPs – Internet service providers to create very high-speed links at quite low cost. Also supports WANs and MANs. 10GB Ethernet is a good solution for connection between numbers of LANs. It only works in full duplex mode.
Ethernet Implementation
Implementation of an Ethernet requires the equipment:
- DCE – data communication equipment
- DTE – data transmission equipment
DCE is the equipment that controls communication within network. These devices include Ethernet adapters or interface cards, Ethernet hubs, switches, repeaters, etc. DCEs for Ethernet implementation must be Ethernet compatible. The source and destinations in a network are referred to as DTEs.
Ethernet HUB
An Ethernet HUB connects number of Ethernet devices with either twisted pair or fiber optic cables. This allows the Ethernet devices to work as a single unit. Hubs containing AUI and BNC connectors support 10Base5 and 10Base2 Ethernet networks.
The benefit of a hub is it works as a repeater. This not only provides data reliability but reduces cost as well. The biggest issue related to hubs is that it sends data to each connected node. This makes the information unsecured and wastes bandwidth. Moreover at peak times excessive collision reduce the throughput. Ethernet switches almost resolve these issues in the same cost. At this time the Ethernet switches have replaced hubs.
ETHERNET SWITCHES
Ethernet switches provide the functionality of hub and resolves problems related to it. A switch transmits data only to the addressed port. This resolves the issue of data security and bandwidth. The difficulty with switches is their complex monitoring (port monitoring and switch monitoring).
Both switches and hubs are available and can be used according to the requirements. For example in small LANs where data security is not an issue, hub can be cost effective. In confidential areas surely the switch is an option.
Conclusion
On the whole an Ethernet is quite easy to implement. Provides flexibility in network installation for new components or management. Supports high data rates at very low cost and above all supports the standard products, regardless of their manufactures.
