Ethernet is a standard communications protocol embedded in software and hardware devices, intended for building a local area network (LAN). Ethernet was designed by Bob Metcalfe in 1973, and through the efforts of Digital, Intel and Xerox (for which Metcalfe worked), “DIX” Ethernet became the standard model for LANs worldwide.

A basic hard-wired LAN consists of the following components:

Two or more computers to be linked together, or networked.
A network interface card (NIC) in each computer.
Ethernet cable to connect to each computer.
A networking switch or networking hub to direct network traffic.
Networking software.

A NIC is installed in each computer, and is assigned a unique address. An Ethernet cable runs from each NIC to the central switch or hub. The switch or hub will act as a relay (though they have significant differences in how they handle network traffic), receiving and directing packets of data across the LAN. Thus, Ethernet networking creates a communications system that allows the sharing of data and resources, including printers, fax machines and scanners.

Ethernet networks can also be wireless. Rather than using Ethernet cable to connect the computers, wireless NICs use radio waves for two-way communication with a wireless switch or hub. In lieu of Ethernet ports, wireless NICs, switches and hubs each feature a small antenna. Wireless networks can be more flexible to use, but also require extra care in configuring security.

Alternate technologies to Ethernet include the passé “Token Ring” protocol designed by IBM, and the far newer asynchronous transfer mode (ATM) technology. ATM allows devices to be connected over very wide distances to create WANs (wide area networks) that behave like LANs. However, for an inexpensive network located in a single building, Ethernet is a well-established standard with a solid record, boasting over three decades of providing reliable networking environments.

The formal designation for standardization of the Ethernet protocol is sometimes referred to as IEEE 802.3. The IEEE (Institute of Electrical and Electronics Engineers) proposed a working group in February 1980 — accounting for the designation [19]80 2[nd month] — to standardize network protocols. The third subcommittee worked on a flavor essentially identical to Ethernet, though there are insignificant variances. Consequently, generic use of the term “Ethernet” might refer to IEEE 802.3 or DIX Ethernet.

WIRELESS VERSUS ETHERNET

In recent years, Ethernet hasn't exactly been fashionable. People are sick of running long wires all over the place, making holes in their walls, and being restricted when it comes to where they can use their computer. Wireless networking has become all the rage - and some predict that it will have killed off Ethernet altogether within a few years.

Wireless networking works by transmitting radio waves through the air. While it isn't yet strong enough to provide networking for a large area, it is quite possible and cheap to set up a cheap wireless networking system large enough to cover an entire house, using nothing more than a wireless router and a wireless card in each computer you want to use on the network. Newer laptops even come with wireless capabilities completely integrated in the form of Intel Centrino, so you can easily connect to wireless networks wherever you go.

Of course, wireless also has its fair share of downsides. Sure, Ethernet requires ugly wires strewn all over the place, but it's also much faster, more stable and more reliable. For large businesses or small businesses that have already had all the wires hidden away in their walls, there is little reason to change over to wireless now. Ethernet is also often more secure - wireless networks are often left unsecured, meaning that anyone can drive past and connect to them. While Ethernet networks can be insecure as well, the network intruder at least has to be inside the building in most cases, not sitting in a car outside.

In turn, wireless networking removes a lot of niggles from Ethernet. The best thing is that you no longer have to worry about wires getting damaged somehow and needing to be tracked down for replacement. Ultimately, which one you use will depend on how adventurous you are, and exactly what you plan to do with your network.

SETTING UP YOUR NETWORK

Configuring a LAN used to be a real pain. You had to manually assign a network address to each device on the network, and keep a record of them to make sure that you didn't use the same one twice - if you did, both devices would stop working. However, modern LANs with routers using a system called DHCP.

DHCP stands for dynamic host configuration protocol. It's a fancy way of saying that when a device connects to the network, it asks the router which addresses are free, and then the router allocates one to it for a limited amount of time. This allows you to connect and disconnect things from your network whenever you want, without having to configure them. Even if your laptop has never connected to a network before, you can just plug it in, and off you go, without needing to know anything about how the network is configured.

In general, to get a modern network up and running, all you need to do is wire up each computer to the router using an Ethernet cable. Often this will be enough to get the computers to see each other, but occasionally you need some extra configuration. In Windows, the easiest way to configure a network is to go to My Network Places on the desktop or the Start menu, and then click 'Set up a home or small office network'.

Once you've done that, any printers or other devices that are connected to any of the computers, or to the router itself, will be automatically shared. If you want to share individual folders between computers, that's also simple to do - just right click them in My Computer, choose Properties then the Sharing tab, and then put a tick in the 'Share this folder on the network' box.

http://www.justvb.net/it/