The Digital Fact Book - Quantel

EEthernetEthernet is a form of Local Area Network (LAN) widely used for interconnecting computersand standardized in IEEE 802.3, allowing a wide variety of manufacturers to producecompatible interfaces and extend capabilities – repeaters, bridges, etc. The datatransmission rate is 10, 100 Mb/s up to 1 and 10 Gb/s, but overheads in packaging dataand packet separation mean actual throughput is less than the ‘wire speed’ bit rate.There are many connection methods for Ethernet varying from copper to fiber optic.Currently the three most common are:10 Base-T The standard for 4-wire twisted pair cable using RJ connectors. This gives extremelylow cost-per-node network capabilities.100 Base-T (a.k.a. Fast Ethernet) 100 Mb/s 4-wire twisted pair cable using RJ connectorsis now becoming very popular. Similar technology to 10 Base-T but uses Cat. 5 cable.Gigabit Ethernet (GigE) Development of existing Ethernet technology to support 1,000Mb/s. This is specified for both fiber and copper Cat. 5e.10 Gigabit Ethernet (10GigE) only functions over copper for short distances – 15 metersusing twinax cable. Using augmented cat. 6 (Cat 6A) cable it may travel twice that distance.For longer range optical fiber is the only answer. This only operates in full-duplex mode – socollision detection protocols are unnecessary. But the packet format and other current Ethernetcapabilities are easily transferable to 10GigE.100 Gigabit Ethernet (100GigE) continues the x10 steps of Ethernet data speedevolution. Destined to travel over optical fiber, it is at the development stage but willdoubtless emerge into the commercial world sometime soon.See also: Hub, CSMA/CD, SwitchWebsites: www.ethernetalliance.orgwww.ethermanage.com/ethernet/ethernet.htmlETSIThe European Telecommunications Standards Institute. Its mission is to produce lastingtelecommunications standards for Europe and beyond. ETSI has 655 members from 59countries inside and outside Europe, and represents administrations, network operators,manufacturers, service providers, research bodies and users.See: AppendixWebsite: www.etsi.org82