4. Networks and the effects of using them Flashcards

Question

Wireless LANs (WLANs) - describe

Answer 1

Do not involve any wiring or cabling Provide wireless network connection overs a short distance They use radio or infrared signal’s instead of cables Devices known as Access Points (APs) are used for a larger range APs usually use spread spectrum technology (larger range)

Answer 2

Advantages All computers can access the same services and resources No cabling is involved The system is more flexible Adding new computers and devices is very easy Cost is reduced and safety is improved Disadvantages Security is an issue Problems and interference can affect the signal The data transfer is slow than in the wired LAN

Answer 3

Any system which allows you to connect to a network or computer through wireless communication Examples : o WLANs o Tablets o Laptop computers o Peripheral devices such as printers

Answer 4

Wi-Fi systems rely on AP (radio frequency technology) to enable the device to receive and send signals Wi-Fi hotspots are places where you can access Wi-Fi (free or paid) Hotspots are found in public places like Airports, hotels and cafés

Answer 5

Bluetooth is an example of wireless personal area networking (WPAN) technology Spread spectrum transmission (radio waves) is used to provide wireless links between to devices such as mobile phones and allow connection to the internet A small home network can be created with this system Used to transfer photos from camera to a mobile phone. It behaves like a mini-LAN

Answer 6

WAN is formed by a number of LANs being connected together through a router or a modem e.g. the Internet is a WAN Some companies set up Private WANs, it is expensive however it comes with a much enhanced security It is common to use an Internet service provider (ISP) for connections to the internet and communicate via this network system Additional hardware is needed for a WAN: Routers, modems and proxy servers

Answer 7

It stands for modulator demodulator. Converts computer’s digital signals (modulates it) into analogue for transmission through telephone lines. Reverse this process- analogue signal from a telephone line into digital for a computer to process the data. (demodulates it) The main use it to connect to computer networks over long distances using existing telephone lines.

Answer 8

They are devices that can have multiple devices connected to them. Main task is to receive data from different ports and send it to each device The information will be received to the device whether its relevant, or not

Answer 9

More efficient than hubs in distributing data. Each device has an access control media address MAC which identifies it uniquely MAC is a number unique to each device connected to the network (like fingerprints) Data sent will have a mac address which tells the source and receiving device.

Answer 10

It connects 2 different types of networks together e.g. a bus and star network It can only connect networks that use the same way for handling messages They do this by changing the form of message to suite the different type of network

Answer 11

Acts like a bridge, yet can link between two or more networks Makes decisions on messages being passed between the networks Formats the messages making it suitable for the new network Reads information about the message and decides where the message should go and the best route for it to get there Used to provide a connection between a network and the internet You need an ISP account to have access to the internet (internet server provider)

Answer 12

Type of server that acts as a buffer between a WAN and a LAN. Retrieves web pages and passes them onto the computer that made a request. Stores any page retrieved on the server, which means that when a different computer requests the same page it would be available. Speeds up the browsing process

Answer 13

The Internet is a worldwide collection of networks. It allows for web browsing, gaming, file sharing, video and email. User can access by web browser.

Answer 14

Web is made up of millions of websites and web pages Web pages are documents on a computer screen containing

Answer 15

Web browsers use URLs to retrieve files. They are standard way of locating on the internet Standard form: 4 numbers e.g. 194.106.220.19 Also alphanumeric form: protcol://site address/path/filename Where; Protocol is usually http Site address consists of: computer name, domain name, domain type, and country code Path is the web page Filename is the item on the page

Answer 16

Operate at 11,000 kilobits/sec. Faster at downloading than uploading They don’t tie up the line while accessing the internet

Answer 17

It is an internal website that is setup internally for companies and can be accessed by employees for the purpose of standard documents or information and many items of information and data. They use internet protocols i.e. a browser

Answer 18

Safer and less chance of hacking Possible to prevent employees from accessing unwanted sites Companies ensure that info. available is specific to their needs Easier to send sensitive messages that remain within a company

Answer 19

To log on to a network, a user must type in a user ID User ID assigns user privilege once user logs in The top level privilege for a network is an administrator: Able to set passwords and delete files from server etc. User privilege may only allow to access their own work area

Answer 20

After typing in user ID, the user will be requested to type in their password. Generally, it is a combination of letters and numbers Passwords are shown as stars (***) so nobody overlooking can see it. Many systems ask for password to be typed in twice as a verification check, in case of input errors To help protect the system, user is has a finite number of attempts If password is forgotten, administrator has to reset it If password is forgotten on a website, it will be sent to your e-mail

Answer 21

The conversion of data to code by encoding it Done by using encryption software Since data is encoded, it appears meaningless to a hacker This technique does not prevent illegal access Necessary to use decryption software to decode the data Used to protect sensitive data e.g. banking details Encryption keys are complex algorithms which makes codes almost unbreakable

Answer 22

Biometric methods: finger print, retina scans, iris scans, face scans - using physical characteristics to authenticate access to systems magnetic stripe cards

Answer 23

A system that scans documents electronically and converts them into a bit map image (a bit is a binary digit and is a 1 or a 0) Then transmitted as a series of electrical signals through the telephone network Receiving fax machine converts the electronic image and prints it out on paper It is also possible to generate fax signals from a computer to allow documents to be sent to a fax machine This saves printing out the document first and then passing it through the fax machine Fax/modem software in the computer converts the image into a form fax machines can recognise

Answer 24

A method for sending text and attachments from one computer to another over a network

Answer 25

Advantages Speed of sending and receiving replies is quick Low cost (no stamps, paper etc.) Not needing to leave home to send the mail Disadvantages Possibility of virus threats and hacking Need for the email address to be correct Inability to send bulky objects via emails Don’t always get immediate response

Answer 26

This is a method of communication between people at 2 or more separate locations It is done in real time and makes use of LAN, if internal, or WAN if through the internet. Uses hardware like; webcam, microphones, speakers and monitors It also uses special software like CODEC converts and compresses analogue data into digital data to send down digital lines. How it works Delegates at one end speak into a microphone and look into the webcam. The other delegates can see them and hear them using speakers and monitors, However there are several problems with these as the conference call often lags and quality is not always high. Also, as travelling tickets increase in price, terrorists can use this way of communicating with each other, increasing risk.

Answer 27

VOIP (Voice over internet protocol) is a method used to talk to people over internet VOIP converts sound (picked up by a microphone) into discrete digital packets that can be sent to a destination via internet The biggest advantage is that it is free and can be used all over the world The biggest disadvantage is that sound quality is usually bad.

Answer 28

Identity and service theft Viruses and malware Spamming (sending junk mail) Phishing attacks (the act of sending an email to a user falsely claiming to be an established legitimate enterprise in an attempt to scam user in different ways

Answer 29

Local Area Network

Answer 30

PCs located usually in the same building computers connected by cable does not require a modem requires a server

Answer 31

Wide Area Network

Answer 32

the internet is the largest WAN PCs connected by telecomunications or wireless mormally spread over various distant areas requires a modem requires a phone/dedicated line computers/LAN can be large distances apart

Answer 33

Wireless Local Area Netweork

Answer 34

links 2 or more devices using some wireless distribution method usually provides connection throughan access point to the wider internet gives the user the mobuility to move around within a local coverage area and still be connected to the network

Answer 35

used to connect 2 mobile devices to each other

Answer 36

INTERnational Network

Answer 37

is a WAN can access from anywhere greater amount of information unlimited access

Answer 38

INTernal Restricted Access NETwork

Answer 39

usually a LAN password controlled pages behind a firewall can set up specific information pages on Intranet systems Information within the school is easily accessible by all users can limit the places where users can go to study no wasted time looking through millions of resources Intranet is better protected for the use of emails/from viruses/from hackers

Answer 40

Local Area Network

Answer 41

Wide Area Network

Answer 42

linked together on a single site

Answer 43

small geographic area

Answer 44

copper cabling

Answer 45

telecommunications link

Answer 46

vast geographic area

Answer 47

fibre optic cabling or wireless technology

Answer 48

expensive peripherals

Answer 49

share resources

Answer 50

any computer to access your files

Answer 51

single software copy

Answer 52

Network Interface Card

Answer 53

communicate with devices on the network

Answer 54

to the file server via a network cable

Answer 55

Wireless Network Interface Card

Answer 56

connect to a wireless router

Answer 57

to each other and the network

Answer 58

NIC, to and from the file server

Answer 59

main computer

Answer 60

more powerful

Answer 61

RAM and hard disk space

Answer 62

file and network security across the network

Answer 63

authorised users log on to the network

Answer 64

application software such as Microsoft Office, user files created by users on the network

Answer 65

file server to the computers

Answer 66

data packets

Answer 67

network connection between the devices on the network

Answer 68

connect to a WAN or the internet

Answer 69

integrated security features

Answer 70

An agreed set of rules for sending or receiving data on a network

Answer 71

communicate with each other

Answer 72

Transmission Control Protocol/Internet Protocol (TCP/IP)

Answer 73

Passwords Levels of access Encryption

Answer 74

unauthorised users

Answer 75

Minimum of 8 characters Alphanumeric Changed regularly

Answer 76

limit the things that users can do on a network

Answer 77

different levels of access

Answer 78

encoding data that is to be sent across a network, making the data unreadable to anybody who intercepts it

Answer 79

encryption key software

Answer 80

Network interface card -Used to allow a device to connect to a network

Answer 81

Media access control address -Number that uniquely identifies a device when connected to a network

Answer 82

Internet Protocol address -A computer is given an op address when connected to a network

Answer 83

Multiple devices connected and sends info to all

Answer 84

Multiple devices connected but only sends to specific one

Answer 85

Connects 2 hubs/switches

Answer 86

Route data packets from 1 network to another

Answer 87

Advantages: -Accesses any time, any device, anywhere -No external storage device -Remote backup -Cloud storage always recovery of data Disadvantages: -Security -Slow/unstable internet is a problem -High costs for large storage capacity -Power cuts -Hackers

Answer 88

Local Area Network -Connected to hubs/switches -Usually within 1 building Advantages: -Sharing of hardware/software -Easy communication -Network administrator Disadvantages: - Easy to spread viruses -Queues for shared recourses -Slower access to internal networks -Higher risk then stand alone computers

Answer 89

Wireless Local Area Network -No wires

Answer 90

-No login -Biometrics -Magnetic stripe -Smart cards -Physical tokens -Electronic tokens

Answer 91

Running this software in the background constantly scans for virus attacks and to prevent them -Needs to be up to date!!

Answer 92

A computer networks consists of 2 or more computers or electronic devices such as printers that have been linked together

Answer 93

Share files Send emails to each other Share resources

Answer 94

Cables Radio signals Telephone lines and satellites

Answer 95

Resources such as printers, scanners and internet can be shared Files and data can be shared Easy to communication with people on the network Access our data from any computer Data can be backed up to a separate computer for security Access huge amount of information and files

Answer 96

If part of the network fails, the whole network can break down Viruses can spread across the network very easily and quickly If a computer on the network is hacked into then all other computers are prone to attack

Answer 97

Servers Clients

Answer 98

Powerful computers that provide ‘services’ to the client computers on the network.

Answer 99

Providing central storage Sharing devices Providing network security Sharing internet connections

Answer 100

File servers Application servers Printer servers Proxy servers

Answer 101

A normal computer that is used to perform everyday tasks and to access info and programs from the server.

Answer 102

LAN WLAN WAN Bluetooth

Answer 103

Local Area Network Usually located in a single room or small building. Private and can only be accessed by people in the room/building. e.g. a school network is only used by students of that school.

Answer 104

Ads: Save money as each computer can share resources Files and data can be shared easily Files and data can be accessed from any computer within the server Data can be sent around very fast Can be monitored easily Disads: Viruses can spread very quickly Security can be an issue The network can become unusable if the main server computer breaks down Slow internet connections High initial cost

Answer 105

Wireless Local Area Networks Similar to LANs but they connect computers together wirelessly without cables. e.g. home networks

Answer 106

Ads: physically safer as no cables are needed cheaper to set up than a WLAN easier to add more computers devices such as printers and scanners can be connected to the network easily computers and devices can be used anywhere in the building Disads: some areas might not be able to pick up the signal security can be an issue wireless signals can be unreliable data transfer is slower than LAN signal range is limited, so useless in a large building

Answer 107

Wide Area Network made up of computers and devices that are connected in a large geographical area created by connecting lots of LANs and individual computers together computers and devices can connect to a WAN using telephone lines, fibre-optic cables and satellite signals need a router or a modem e.g. the internet

Answer 108

Ads: computers can be connected over wide areas files and data can be shard over a large area users can communicate very quickly, over large areas e-commerce computers and devices can be used anywhere Disads: security can be an issue easy to accidentally download viruses data is transferred across a WAN is a lot slower than a LAN monitoring a WAN is difficult

Answer 109

Wireless Personal Area Network (WPAN) devices can connect to each other between 1 and 100 metres away from each other

Answer 110

ads: very easy to connect not easy to disrupt works wirelessly so no messy cables very little power needed disads: limited signal range slow data transfer very secure

Answer 111

a computer network that connects computers worldwide

Answer 112

a private network within a company and it is only available to staff members of the organisation

Answer 113

It is a method of data storage where data is stored on offsite servers. The physical storage covers hundreds of servers all over the world so data can be accessed anywhere.

Answer 114

Data in clouds is stored on more than one server so that clients can access data at all times even during maintenance and repair.

Answer 115

Public cloud- customer and cloud storage provider are different companies Private cloud- Storage provided behind a firewall. Customer and cloud storage provider are one unit Hybrid cloud- Combination of private and public.

Answer 116

Files can be accessed anytime, on any device, anywhere provided the user has internet access No need to carry around storage devices and use only specific devices Provides backing up and recovery of data Offers almost unlimited storage

Answer 117

If internet connection is slow, accessing files could be hard Costs can be high if lots of storage is needed Failure of cloud storage can cause permanent loss of even backup data.