What is it?
Ethernet is the most widely-installed local area network technology. Fast Ethernet and Gigabit Ethernet raised the capacity from 10 megabits to 100 megabits and then 1,000 megabits.
Following the ratification of the 10 Gigabit Ethernet standard, suppliers are now offering ways of increasing throughput further by combining 10-gigabit connections.
IT education advisers recommend Ethernet skills as a sound foundation for a career, as it can provide skills that can be applied to desktop, backbone, wide area and metropolitan networking and, with a little adjustment, wireless.
Where did it originate?
Ethernet was developed at Xerox Parc by Bob Metcalf, who later founded 3Com, and is responsible for the Zigbee wireless networking standard.
Originally devised as a way of connecting a personal computer to a printer, Ethernet soon developed into a way of connecting multiple devices on a single wire.
Xerox passed control of Ethernet to the IEEE's 802 committee, set up to establish standards for Lan technologies. The IEEE 802.3 Ethernet standard appeared in 1985. The Fast Ethernet standard was approved in 1995, Gigabit Ethernet in 1998, and 10 Gigabit Ethernet in 2002.
What is it for?
All versions of Ethernet can be used for any kind of networking, from local to wide area.
What makes it special?
From the outset, Ethernet appealed to users because it gave each their own dedicated bandwidth. Although in practice, this was less than half the nominal capacity (five megbits rather than 10 megabits).
Each new version of Ethernet has retained compatibility with older implementations, extending rather than changing the standards. Even though new media such as fibre optics are involved, Ethernet skills evolve on a stable foundation.
How difficult is it to master?
Learning Ethernet is a serious undertaking. You can find two-day introduction to Ethernet courses, but you would be better off putting the £700-plus these courses cost towards a certification course which teaches Ethernet with associated networking skills. These involve about four weeks of training and are priced accordingly.
Where is it used?
In local area networking, Ethernet's share is being nibbled away by wireless. Last year, wireless overtook Ethernet in home networking in the US.
What systems does it run on?
Ethernet is at the heart of many networking products and technologies from Cisco, 3Com, IBM, Hewlett-Packard and other suppliers.
Not many people know that...
The second generation, Ethernet II, was sometimes called Dix after its sponsors: Digital, Intel and Xerox.
What is coming up?
By the end of the decade we may have 40 Gigabit and possibly 100 Gigabit Ethernet, although overcapacity in the carrier market has taken momentum from these developments.
Rates of pay
Network administrators earn about £20,000 a year and network engineers can earn £30,000. Salaries can be much higher for senior engineers and network architects. Certification such as the CCNE (Cisco certified network engineer) is often required.
Ethernet courses are widely available from independent training organisations and suppliers such as Cisco, 3Com and IBM. There are plenty of free internet tutorials and, although many are old, the basic principles remain the same. The best book is Charles Spurgeon's Ethernet: A Definitive Guide, published by O'Reilly.