Many types of networks exist, but the most common types of networks are Local-Area Networks (LANs), and Wide-Area Networks (WANs). In a LAN, computers are connected together within a "local" area (for example, an office or home). In a WAN, computers are farther apart and are connected via telephone/communication lines, radio waves, or other means of connection.
(LAN):-
Originally, only medium to large-sized businesses could afford the cost of networking hardware. In the last decade, prices have rapidly dropped as new technology has developed, and it is now possible to grab a basic 4-PC 10Base-T home networking kit for under $150. The affordable price and added convienence of having a LAN has made it commonplace to see networks in many homes and offices. Each PC in a LAN is able to access shared files and devices anywhere on the LAN. This makes the sharing of expensive devices, such as laser printers or large removable storage drives, a cost-effective alternative to purchasing a device for every user.
If you decide to use Ethernet for your LAN (which we recommend you do), you can choose from 10Base-T (10 million bits per second, or 10 Mbps) or 100Base-T (100 million bits per second, or 100 Mbps), which is usually refered to as Fast Ethernet. 10Base-T is used mostly for home and small office networks, because it offers both affordability (around $20-30 for a network card, and $80 for an 8-port hub) and decent performance. For large businesses, a 100Base-T solution may be required if there are a large number of PCs connected to the network, or if large amounts of data is frequently transferred.
There are three different types of cabling for Ethernet networks. Unshielded Twisted Pair (UTP) is the most popular type of cabling, and the one we recommend because of its wide availibility and low price. The other two types are coaxial and Shielded Twisted Pair (STP). STP cable provides more shielding against outside Electromagnetic Interference (EMI) than UTP, but is more expensive. We've never had any problems with EMI, so we suggest the cheaper UTP. Coaxial uses much thicker and more expensive cable, and must be run in a ring configuration, from PC to PC, unlike Twisted Pair, which is run directly from each computer to a port on the hub, making wiring more convienent in most cases.
Ethernet networks require a Hub, a hardware device that all PCs on a network are connected to by cabling. The hub manages receiving and transmitting data from networked devices. Hubs come in many different port configurations, but you will probably need a 4, 8, or 12 port hub, depending on the number of PCs you want to connect together. Each port supports a single 10Base-T connection from a PC or peripheral. If you're using Coaxial cable, you need to find a hub with one Coaxial port and minimal Twisted Pair ports. There are both Manageable Hubs, which allow advanced configuration of Hub properties via a software package, and Standard Hubs, which are cheaper, and usually used for home or small office networks. We recommend purchasing a standard hub, since the extra features included in Manageable Hubs are not useful for a home or small office network. Since you will probably purchase a standard hub, we'll discuss the three types of standard hubs next.
(WAN):-
A WAN (wide area network) is a geographically dispersed telecommunications network and the term distinguishes a broader telecommunication structure from a local area network (LAN). A wide area network may be privately owned or rented, but the term usually connotes the inclusion of public (shared user) networks. An intermediate form of network in terms of geography is a metropolitan area network (MAN).
Wide area network services can be classified in many ways. First, there are services by public carriers and those provided through private user facilities like microwave or private optic cable networks. Second, services can be based on relatively permanent connections (switched or dial-up). Services can also be based on analog information flows or digital flows, and on circuit or packet-switched technology.
Today, WANs (Wide Area Networks) are created using many types of services for the small business and home business users. The only constraint is what your local operating company (PacBell, Bell Atlantic, Ameritec, etc.) will provide as service and / or if a new CLEC has competing services that will allow you to access these services. Any time that you leave your LAN environment and go on the PSTN network, that is called accessing the WAN. Your traffic is then routed to the local exchange via the connection or line (typically analog modem, ISDN, Frame Relay, T1). The traffic is then sent across the network to the final destination that you have pointed your traffic (data/voice) to.
(MAN):-
A MAN (metropolitan area network) is a network that interconnects users with computer resources in a geographic area or region larger than that covered by even a large local area network (LAN) but smaller than the area covered by a wide area network (WAN). The term is applied to the interconnection of networks in a city into a single larger network (which may then also offer efficient connection to a wide area network). It is also used to mean the interconnection of several local area networks by bridging them with backbone lines. The latter usage is also sometimes referred to as a campus network.
Examples of metropolitan area networks of various sizes can be found in the metropolitan areas of London, England; Lodz, Poland; and Geneva, Switzerland. Large universities also sometimes use the term to describe their networks.
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