Networking

Understanding Computer Networks

O A computer network is a collection of

computers, printers, and other devices

that are interconnected by communication

channels. Computer networks facilitate

communications among users and allow

users to share resources.

Advantages of Networks

O Sharing Resources,

O Security,

O Communication,

O Education,

O Project Management .

Drawbacks of Networks

O Installation and maintenance cost

O Viruses and Trojan horses

O Network can be useless in the case

of a crashing server

O Identity theft

O Internet crimes

Network Types

There are three general categories

of networks:

O LAN (local area network)

O MAN (metropolitan area network)

O WAN (wide area network)

LAN (Local Area Network)Usually, if the devices on a network are in a

single location, such as a building or a

group of rooms, they are called a local area

network (LAN). LANs usually have all the

devices on the network connected by a

single type of network cable or wireless

connection.

MAN (Metropolitan Area Network)

A metropolitan area network (MAN)

interconnects users with computer

resources in a geographic area or

region larger than that covered by a

local area network (LAN) but smaller

than the area covered by a wide area

network (WAN).

MAN (Metropolitan Area Network)

WAN (Wide Area Network)

O If the devices are scattered widely,

such as in different buildings or

different cities, they are usually set

up into several LANs that are joined

together into a larger structure

called a wide area network (WAN).

WAN (Wide Area Network)

Comparing LAN, MAN and WAN

Network Components

Media

O The term network media refers to the pathways along which data travel. Network media is the actual path over which an electrical signal travels as it moves from one component to another. It provides connections between the network computers, peripherals, and devices in the network.

O There are four types of media technologies used in computer networks:

Coaxial cable

UTP (unshielded twisted pair)

Fiber Optic Cable

Wireless

Network Devices

O Computer networking devices

are units that mediate data in a

computer network. Computer

networking devices are also

called network equipment or

communication devices.

NIC (network interface card)

Bridge

O A bridge device filters data

traffic at a network boundary.

Bridges reduce the amount of

traffic on a LAN by dividing it

into two segments.

Switch

O A network switch is a small

hardware device that joins multiple

computers together within one local

area network (LAN).

Router

O When two or more networks

must be connected, a router is

usually necessary.