Knowt
Chapter 4
(a) Describe the purpose of a web browser.
Retrieves code from the server/Downloads information resources
Interprets the code as a web page/Uses page resources to build a web page/Runs the code
The web page is displayed/Renders web page to view
Allows the user to navigate to other information
Runs 'client-side' scripts on the web page
(b) A company may use an intranet or an extranet. Describe the differences between an intranet and an extranet.
Intranet shares data within an organisation whereas Extranet shares content with customers/suppliers
Intranet allows communication within the organisation whereas
Extranet allows communication with customers/suppliers Intranet is owned is by a single organisation whereas Extranet can be used by several organisations
Extranet is part of a company’s intranet
Extranet can lead to more security breaches
Members of the team can use video-conferencing to join business meetings from different locations around the world. Describe, giving reasons, three disadvantages of using video-conferencing for business meetings rather than meeting in person.
More difficult to carry out projects as individuals are working on their own
Difficult to form relationships with staff as individuals are working on their own
Requires a good/fast/reliable internet connection as documents/images may require more bandwidth
Requires specialist hardware/software can be expensive to purchase
Time zone differences as staff work in other parts of the world/time of meeting may be difficult
May require training this may take time/expensive
Communication issues causing lip syncing/lagging
Disconnection issues/speed of the internet members of the meeting miss sections/meeting
Background noise/echo could be distracting
Users could be distracted not pay attention to the meeting
Many media companies now provide media streaming for users to watch their television programmes.
(a) Explain what is meant by the term media streaming.
Live or recorded content
Delivered to computers/mobile devices via the internet
Played back in real time/on demand.
Allows the user to view the media without downloading it
(b) Describe the benefits and drawbacks of media streaming.
Benefits
Instant access to the media
Saves time rather than downloading/going to the shops
No need for storage space as there is no copy
Drawbacks
Requires an internet connection
Requires a good internet/bandwidth connection otherwise buffering
Don’t get to keep the product
Online security issue related to the subscription
Technology could fail in the middle of the stream If media is downloaded it is time locked
A company uses an extranet.
(a) Explain what is meant by an extranet.
An extranet is part of a company's intranet
The company gives permission for customers and suppliers to access it
Enables businesses to exchange information over the internet in a secure way
Requires credentials/username and password to access it
(b) Describe the differences between the internet and an extranet
Internet allows public access to information whereas Extranet allows limited access
Extranet is more secure
The internet is not owned by anyone whereas the Extranet is owned by a company
More information on the internet
A teacher provides revision lessons during the holidays. The teacher plans to use web-conferencing for the lessons.
(a) Explain what is meant by web-conferencing.
Form of real-time/live/online communication
Multiple users/devices connect using the internet
All users see the same screen.
Communication using video cameras/microphones
(b) Evaluate the use of web-conferencing in this scenario.
Positives
The students save time as they do not need to travel to the school
The students save the cost of travelling to the school.
The school saves costs as it does not need to open in the holidays
Students and teachers can work from anywhere in the world
Can be recorded for students who miss the lesson
Negatives
Hardware/software could be expensive
Requires a good/reliable internet connection
There could be issues with child protection
More difficult to concentrate/motivate
If the hardware breaks/loss of connection/lack of hardware then the student cannot participate
Only students with the correct specialist devices will be able to access
A company uses an intranet. They are considering using an extranet. Compare an intranet with an extranet. Your answer must include similarities and differences.
Similarities
Both have shared content
Both use internet technologies / TCP-IP
Both have restricted access
Both sit behind a firewall
Differences
Intranet shares data within an organisation whereas extranet shares content with external users and employees
Extranet is part of a company’s intranet
Intranet allows communication within the organisation whereas extranet allows communication with customers / suppliers
Extranet can lead to more security breaches
Intranet is owned is by a single organisation whereas extranet can be used by several organisations
The manager of an organisation is planning a meeting of its directors. The manager plans to use audio-conferencing for the meeting.
(a) Explain what is meant by audio-conferencing.
Audio-conferencing is where two or more people in different locations use technology to hold an audio call
All the participants dial into a central system that connects them
Removes the need to directly call each other
(b) The organisation could use video-conferencing for the meeting. Describe three advantages of using audio-conferencing rather than video-conferencing in this scenario.
Easier to set up
Does not need specialist equipment therefore saves money
No issue with lip syncing
Less bandwidth is needed therefore reduces hanging / freeze
More privacy as they do not use cameras
A company has an extranet. Explain what is meant by an extranet.
Extranet is a network controlled by a company
Restricted/private network
Allows access for partners/vendors/suppliers
Allows access for authorised customers
A headteacher is planning to hold a video-conference with headteachers from other schools. The headteachers already have basic internet connected desktop computer systems including a monitor, keyboard and mouse.
Identify three pieces of additional hardware they need in order to participate in a videoconference.
Microphone
Video camera/webcam
Speakers/headphones
Compare the similarities and differences between Bluetooth and wi-fi.
Similarities
Both use wireless communications
Both use radio frequencies for communication
Both allow several devices to be connected
Both use security when sending data
Differences
wi-fi has a faster data transfer rate
wi-fi has a greater range of transmission
wi-fi uses key matching encryption
Bluetooth uses WEP and WPA security together
wi-fi can be broadcast
wi-fi connects more devices
Bluetooth has a lower frequency than wi-fi
People can watch a movie either by streaming or from a Blu-ray disc.
Give two advantages of watching the movie by streaming rather than from a Blu-ray disc
Cheaper than buying the Blu-ray player
Streaming works on different internet connected devices
—>Streaming uses a simpler interface
A family has a number of different devices connected to the internet.
(a) Identify three items of computer hardware that may need to be purchased in order to set up a computer network so the devices can use the internet
Network cards
Router
Switch/hub
(b) Arjun is a member of the family. He uses the internet to carry out research and send work to his office. Describe other ways he could make appropriate use of the internet
Email
Online chat//Instant message
VOIP
Online conference
Streaming music/video/TV on demand
Gaming
Use of the Cloud
Newsgroups
FTP
(c) Arjun uses the internet to carry out research for his work. Describe the drawbacks of Arjun using the internet for research.
User id and password can sometimes be easily guessed
Passwords can be hacked with key logging software
Passwords can be hacked by using random password generators
Others can see the details being typed in
If the home computer saves the log in information, then anyone can access
If the user does not logout, then others can access data
Compare and contrast an intranet with the internet.
Similarities
Both are communication systems
Both use internet technologies
Both use HTML to write the web pages
Both are information systems
Both are networks
Differences
An intranet has private access whereas the internet has public access
An intranet is policed whereas the internet anyone can post material
The data on an intranet is moderate whereas /the internet is not moderated
The data access on an intranet is more secure than the internet
Internet has greater amount of information than intranet
Intranet is within an organisation whereas the internet is world-wide
Data in the intranet is more relevant/reliable than information found on the internet
Define the following internet terms
(a) Hyperlink
Link from an image or word
Link containing a URL//URL code
When clicked on it takes you to a web page or position in a webpage
(b) ISP
Internet Service Provider
A company that provides users with access to the internet/internet services
Usually broadband
A bridge and a router are examples of networking devices.
(a) Explain the differences between a bridge and a router.
A bridge connects two LANs that use the same protocol
A bridge creates a single LAN from separate parts
A router allows data packets to be sent to LAN/WAN
A router connects a LAN to a WAN
(b) IP addresses are used in computer networks. Explain what is meant by an IP address.
Internet Protocol address
Unique identifier
IP addresses must be different for each device on a network
All devices connected to the internet use IP addresses
Determines the electronic location of the device
(c) Explain the purpose of a routing table
Used to determine where data packets will be directed
Stores route information
Stores IP addresses
Identify three different network communication devices and describe what each one does.
Device 1 Router
Description
Allows a LAN to be connected to a WAN/Internet
A router allows data packets to be sent to LAN/WAN
Device 2 Hub
Description
Connects computers/devices so data can be broadcast to all devices Expands a LAN
Network interface Card (NIC)
Connect computers/devices to a network
Device 3 Bridge
Description
Connects two LANs of the same protocol together
A bridge creates a single LAN from separate parts
Device 4 Switch
Description
Connects computers together to form a LAN
Allows data to be sent to individual devices
The hotel uses both a WAN and a WLAN. Describe the differences between a WAN and a WLAN.
WAN
Wide Area Network
Over a large geographical area
Tends to use satellite technology
WLAN
Wireless Local Area Network
Covers the hotel site
Uses Wireless technology
Compare and contrast the features of a switch and a hub
Comparison
Both are network devices
Both are hardware devices
Both have computers and devices connected to them
Both send data to devices//Both are communication devices
Contrast
In a hub data packets/data are broadcast to every device connected to it
A hub is less secure than a switch in distributing data
Switch checks the data packet
Switch sends to an appropriate device
To gain full marks both contrast and comparison is needed
Choose two network devices.
Actuator Bridge Database DVD Hub Linker Monitor Printer
Hub
Bridge
An organisation uses the internet and an intranet.
Explain how the purpose of the internet differs from the purpose of an intranet
Internet is used to share and distribute information outside the organisation whereas the intranet within an organisation
Internet is used to send and receive emails and messages outside the organisation whereas intranet sends and receives messages within an organisation
The intranet meets the needs of the organisation whereas internet aims to meet the needs of everybody
The internet facilitates collaboration with others whereas the intranet is only used to collaborate with other members within an organisation
The internet is used to browse the World Wide Web
Write down the most appropriate network device to match the following statements. Your answers should be different in each part
(a) This network device checks the data packet arriving from one computer and sends the data to a specific computer.
Switch
(b) This network device sends the data packet from a computer to all devices connected to it.
Hub
(c) This network device connects a LAN to the internet.
Router
(d) This network device connects one LAN to another with the same protocol.
Bridge
Describe uses of a company intranet.
Send/receiving emails
Send/receive attachments/files
Internal file transfer within the company
Allows the creation of extranets
Surf internal information/webpages
Sharing/use of applications/resources
Social networking is used to communicate with friends; this is one use of the internet. Describe four other uses of the internet.
Email
Use of the web
Newsgroups
Online chat
Streaming
Internet telephone
Online conferencing
Gaming
File transfer
A major part of the everyday use of the internet is social networking. Currently some social networks are not policed. The owners of a website have full discretion on what material is removed and what is allowed to be kept. Discuss the benefits and drawbacks of policing social networking sites
Benefits
Can reduce cyber bullying/hate speech/sexual harassment
Can reduce social media from being used for illegal activities
Can reduce the ability to incite violence/trolling
Could prevent people from being subjected to inappropriate messages
Can reduce illegal/inappropriate images
Drawbacks
Freedom of speech is reduced
Would be very difficult to police as there is a massive amount of information
Different rules in different countries and social media crosses borders
Very costly to create an effective deterrent
Could force individuals to use other un-policed methods of communication
Who decides what is acceptable and what is not acceptable
Privacy issues as people checking could read messages
Difficult to police as users can be anonymous
To gain full marks there needs to be benefits and drawbacks
A family has purchased a wireless router for use in their home to allow their devices to be connected via WiFi to form a wireless local area network (WLAN). When the family purchased the wireless router they were advised to change the default password.
(a) Explain why they should change the default password.
So that other people cannot access the router using the known default password
As it is wireless the password could be cracked from outside easily and then used for free by others
So that people cannot make changes to/access personal data on the router
It would increase security of the data
(b) Describe the process of using WiFi to connect to a WLAN
The computer/device sends data to its wireless adapter
The data is converted into radio waves
The radio waves are transmitted
A wireless adapter receives the radio waves
Radio waves are converted into data
The computer initiates a handshake with the wireless router
The wireless router responds
Establishes a session/pairing
Wireless router checks the password/key is correct
Data is transmitted
User has to enter a password/passkey/automatic entry of key for known connections
(c) Their son produces large complex diagrams on his desktop computer at home. He needs to be able to access the diagrams when he is at university. Even if reduced in file size, the diagrams would be too large to send using email.
Describe in detail how he could transfer the diagrams from his home desktop computer to be able to access them at university, without using additional hardware.
Create a cloud storage account
Ensure sufficient storage in the cloud account
Log into the cloud at home
Upload/transfer the diagrams from his home computer to the cloud
At university: access/login to his cloud storage account
At university: download/access the stored diagrams
(d) One of the parents in the family works for a government department and sends sensitive data from their home computer to the office.The data is encrypted before being sent to ensure it is harder to understand if it is intercepted.
Describe other preventative measures that could be taken to avoid network security issues.
Install security devices/firewalls
Use a VPN
Install security software/anti-virus/anti-spyware
Set up security settings in the router/operating system
Data backup in case of data loss/corruption
Restrict access to the network infrastructure
Train the family in the safe and secure use of the equipment
Not opening emails/attachments from unknowns/phishing emails
Not downloading files from unknowns/phishing emails
Use a dongle to restrict use of software
Streaming movies and music is replacing downloading or purchasing a physical copy of the files. Describe the advantages and disadvantages of streaming files rather than using other methods.
Advantages
Files can be larger therefore it can save physical storage space
More likely to get the music you need
More likely to get more up to date music
Can be accessed in more places as only need the internet
Don’t need physical storage space
Don’t need optical drives to view/listen to movie/audio
Can be viewed on mobile devices with internet connection
Copyright owners have more control over who can watch the movie/listen to
the audio as no physical copy exists to be copied/pirated
Don’t have to wait for the whole/large file to be downloaded before viewing
Physical copies can be lost/stolen/damaged rendering them useless/have to buy again but steamed movies are always available
Disadvantages
Needs a connection to the internet
Never own a physical copy of the file
The playback is dependent on the internet connection therefore may not be as good a quality
A subscription may be needed to be paid therefore may be more expensive
To gain full marks there needs to be advantages and disadvantages
Computer data can be stored on physical storage devices. Data can also be stored in the ‘cloud’.
Explain what is meant by the cloud, giving advantages of storing data in the cloud compared with physical storage devices
what is meant by the cloud
Data is stored on offsite servers
Many servers in many locations
Data is stored on more than one server
Uses data redundancy
Cloud is an online service/data storage
advantages
The cloud has greater storage capacity than other methods
The data could be sent directly to the cloud from any device
Access the data from any device/anywhere
Easier to add storage capacity
Lower capital outlay
The owner would only pay for the storage they used
Backup up tends to be automatic
Cloud is more robust
Cloud is more secure as it is password protected
A variety of network devices can be used to connect computers together
(a) Complete the following sentences using the most appropriate network device from the list. Your answers must be different in each case.
an access point, a bridge, a hub, a modem, a network interface card, a switch
A device used to connect a Local Area Network (LAN) to another LAN that uses the same
protocol is called a bridge
A device used to convert a computer’s digital signal to an analogue signal for communication
is called a modem
A device that connects a number of other devices and sends data to one specific device only
is a switch
An item of hardware in a computer that allows a device to connect to a network is a network interface card
A router is used to connect a LAN to the internet. A message is sent from the router to another router.
(b) Give the name of the part of the router where the IP addresses are stored.
Routing table
(c) Explain how the data from a router is routed.Data is sent in data packets//uses data packets
Each data packet contains an IP address of the next router
The router reads/checks/inspects the IP address
It checks the IP address against its routing table
Data packet is sent to the router with the IP address
The router uses the IP address to work out the best route/destination computer
The router stores the IP addresses
