introduction to information technology ( network)

8/4/2019 Introduction to information technology ( network)

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ITD12103 - Introduction toInformation Technology

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Chapter 4

Network


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Chapter Contents

Section A: Network Building BlocksSection B: Wired Networks

Section C: Wireless NetworksSection D: Using LANs


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Network Building Blocks

Network ClassificationsLAN Standards

Network DevicesClients, Servers, and PeersPhysical Topology

Network LinksCommunications Protocols


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Question

Networks come in many sizes and use manydifferent technologies, yet they all need tocommunicate with each other. What is the keyto network intercommunication?

A. Packet switchingB. Network protocolsC. Network topologyD. Peer-to-peer technology


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Network Classifications

Personal Area Network (PAN) interconnection of personal digital devicesLocal Area Network (LAN) usually connectscomputers in a single buildingMetropolitan Area Network (MAN) publichigh-speed network with range of about 50miles

Wide Area Network (WAN) consists of several smaller networks


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LAN Standards

LAN technologies are standardized by theInstitute of Electrical and ElectronicsEngineers (IEEE) Project 802 Local Network Standards

IEEE 802.3ARCnet

Token RingFDDIEthernet


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Network DevicesEach connection point on a network is referred to as anodeTo connect to a LAN, a computer requires network circuitry, sometimes referred to as a network interfacecard (NIC)A networked peripheral, or network-enabledperipheral, is any device that contains network

circuitry to directly connect to a network A network device, or network appliance, is anyelectronic device that broadcasts network data, boostssignals, or routes data to its destination


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Network Devices


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Clients, Servers, and PeersNetwork devices can function as clients or as servers

Application serverFile server

Print serverNetworks that include one or more servers canoperate in client/server mode


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Physical TopologyThe arrangement of devices in a network is referred to as itsphysical topology

StarRing

BusMeshTree

Two similar networks can

be connected by a devicecalled a bridgeGateway is a generic termfor any device or softwarecode used to join two networks


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Network Links

A communications channel, or link, is aphysical path or frequency for signaltransmissions

Bandwidth is the transmission capacity of acommunications channelBroadbandNarrowband


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Communications Protocols

Rules for efficiently transmitting data from onenetwork node to another:

Divide messages into packetsAffix addresses to packetsInitiate transmissionRegulate flow of dataCheck for transmission errorsAcknowledge receipt of transmitted data


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Communications Protocols

A packet is aparcel of data thatis sent across acomputer network

Circuit-switchingtechnology vs. packet

switching technology


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Wired Networks

Wired Network BasicsEthernetEthernet EquipmentEthernet Setup


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Question

Suppose youre setting up a network in your home or apartment. You want all of the computers to accessthe cable modem that provides Internet access. What

is the one additional component that you shouldpurchase to tie the network together?

A. A routerB. A network interface cardC. A file serverD. A HomePlug Ethernet port


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Wired Network Basics

A wired network uses cables to connectnetwork devicesWired networks are fast, secure, and simple toconfigureDevices tethered to cableshave limited mobility


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ITD12103 - Introduction toInformation Technology 18

Ethernet

Simultaneously broadcasts data packets to allnetwork devicesIEEE 802.3

CSMA/CD protocolVary in speed from 10Mbps to 100Gbps


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Ethernet

On an Ethernet, datatravels on a first-come,

first-served basis. If twoworkstations attempt tosend data at the sametime, a collision occurs.That data must beresent.


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Ethernet Equipment


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Ethernet Equipment

Ethernet adapter (designed to support theEthernet protocols)Network hubNetwork switchNetwork router

RJ45 connector


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Ethernet Setup


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Ethernet Setup


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Wireless Networks

Wireless BasicsBluetoothWi-FiWi-Fi EquipmentWi-Fi Setup


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Question

When youre setting up a wireless network, you see anoption asking if you want to broadcast the network SSID.You should:

A. Change the default SSID and broadcast it whileyou set up the network.B. Turn SSID broadcasting off so that hackers dontknow the networks encryption key.

C. Make sure SSID is broadcasting so that yournetwork is protected by strong encryption.D. Activate SSID broadcasting or else the network devices wont be able to send data to the router.


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Wireless Basics

A wireless network transports data from onedevice to another without cables or wires

RF signalsTransceiver

MicrowavesInfrared light

Slower than wired networksSecurity concerns


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Bluetooth

Bluetooth is a short-range, wireless network technology designed to make its ownconnections between electronic devices,without wires, cables, or any direct action froma user


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Wi-Fi

Wireless networking technologies that arecompatible with EthernetMIMO technology uses two or more antennasto send multiple sets of signals


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Wi-Fi Equipment


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Wi-Fi Equipment

If your computer is not pre-equipped withwireless circuitry, you can purchase and installa Wi-Fi adapter


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Wi-Fi Equipment

Wireless network setupsWireless ad-hoc network Wireless infrastructure network

Wirelessaccess pointWirelessrouter


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Wi-Fi Setup

Set up the routerConnect to the router with a computer

Configure the routerAccess the router setup utilityCreate a new router password


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Wi-Fi Setup

Enter an SSID for the network Activate WEP, WPA, or PSK and create anencryption keySet up the wireless workstationsConnect an Internet access device


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Wi-Fi Setup


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Using LANs

LAN Advantages and ChallengesSharing FilesSharing PrintersLAN PartiesTroubleshooting


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Question

There are many ways to share files among thecomputers on a network. Which one of thefollowing is the LEAST secure way to share files?

A. Use a file server.B. Activate file sharing for the root directoryof all the computers in the network.

C. Designate specific folders on yourcomputer as shared.D. Put files you want to share in the Public

folder.


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LAN Advantagesand Challenges

LANs enable people to work togetherSharing networked software can reduce costs

Sharing data on a LAN can increase productivitySharing networked hardware can reduce costsSharing networked hardware can provide access

to a wide range of services and specializedperipheral devices


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LAN Advantagesand Challenges

Resources become unavailable when network malfunctionsNetworks may be vulnerable to unauthorized access

More vulnerable than standalone computersWireless networks can be tapped from a snoopingcomputer

Networked computers are susceptible to an increasingnumber of worms, Trojan horses, and blended threats


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Sharing Files

If you use Windows,it automaticallydetects availableLANs any time youturn on a workstationTo connect to ashared resource, youmight be asked for auser ID andpassword


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Sharing Files


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Sharing Files


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Sharing Printers

Three setups allow for printer sharing:Set up printer sharing using a workstation printerSet up printer sharing using a print serverInstall printer with built-in networking


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Sharing Printers

You can designatethe printer attachedto your computer assharable over thenetwork.


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Troubleshooting

Network problems can stem from a variety of sources

CablesSignal strengthSecurityInterference

Network devicesSettings


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True/False Questions

In a network, a server is a computer that providesservices to other computers called peers.Star, ring, and mesh are examples of network

topologies.When you send an e-mail message over a network, itis chopped up into packets.The IP address assigned to your computer on theInternet is derived from your computers MACaddress.Some network technologies use home telephone or

electric cabling for computer networks.


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The most popular type of wired network is Ethernet.Network speeds are measured inmegabytes and gigabytes.Many wireless networks use radio wavesto transmit data.Bluetooth is a wireless technology usedfor WANs.


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ITD12103 - Introduction to 48


A wireless infrastructure network uses acentralized broadcasting device, such as awireless access point or router.Wireless networks are less secure than wirednetworks.WEP, WPA, and PSK are examples of Wi-Finetworks.Public key encryption uses a public key toencrypt messages, but a private key is required

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