3.2 LAN (local area
network)
Cody L. Horton (1998). »In its simplest form, a LAN is a
communications network that provides users of workstations with a transmission
medium and a path for sharing local and remote computer resources» . A LAN
consists of the network cable also called network media, protocols, and network
interface cards (NIC), servers, workstations (clients), and other network
devices. LANs are separated into two broad categories, peer-to-peer and
server-based. The distinction between peer-to-peer and server-based networks is
important because each category provides different capabilities.
1.11. 3.2.1. Peer-to-Peer Networks
Connection between similar device (computer to computer) for
sharing information .Peer-to-peer networks are suitable for small organizations
where the network will consist of 10 or fewer computers. A peer-to-peer network
is workable in situations where network security is notimportant, and no
centralized network administration is required. In a peer-to-peer network,
all
Computers on the network can function as both clients and
servers. In this type of network, each client can share resources with any
computer on the network, and there is no centralized control over shared
resources. The peer relationship means that no one computer has higher access
priority or heightened responsibility to provide shared resources or network
management.
Peer-to-peer networks are not capable of handling high volumes
of network traffic, but in networks of 10 or fewer they provide an easy means
of sharing data and resources. Each computer in the peer network has the
responsibility of administering its own user database, which means that the
users must have a password and user account on even' computer in the network.
Peer-to-peer networks are less expensive and easier to install than
server-based networks, but they also provide less functionality and are not
very expandable. While it may appear that peer-to-peer networks are unworthy of
consideration because of their limitations, keep in mind that peer-to-peer
networks offer some powerful inducements particularly to smaller organizations
and networks. Peer-to-peer networks are the easiest and least expensive types
of networks to install. Most peer-to peer networks require only an operating
system, such as Windows XP or Windows for Workgroups, network interface cards,
and a common network medium. Once the computers are connected, users can
immediately begin sharing information and resources. [Tittel, Hudson, 1998]
1.12. 3.2.2 Server-Based Networks
Server-based networks, also known as "client/server" networks,
rely on special purpose computers
Called servers that provide centralized management, coordinate
and support to other computers, and resources on the network. In a server-based
network, dedicated servers are installed for the purpose of providing network
services such as: user logons, maintaining the authorized user accounts
database, storing files, providing resources and shared applications to users,
and providing network security.
There are a number of reasons to implement a server-based
network, including centralized control over network resources through the use
of network security control over the network using the server's configuration
and setup. Server-based networks are scalable and allow for future network
growth and expansion. These networks are robust and can support a large number
of users depending on how the server is configured. Server-based networks can
be tailored to meet the needs of small or large organizations, and they can
handle high volumes of network traffic. Server-based networks are much more
powerful than peer-to-peer networks, but they are also more expensive than
peer-to-peer networks. Additionally, server-based networks require more
administration, more training, and higher levels of technical expertise to
implement than required in peer-to-peer networks.A WAN provides connectivity
between more than one LAN, and most WANs are a combination of LANs and other
types of communications components connected by communication links called WAN
links [MS PRESS, 1996].
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