Network Technologies

Question 1

What is a Network?

Answer 1

A network is a group of two or more computers
which are connected together.

The connections between computers can be wires, fibre
optic cables, microwave or radio links, satellite
communication or a combination of these methods

Question 2

What is a LAN?

Answer 2

A Local Area Network (LAN) is a network in which the computer systems are situated relatively close to each other, for example in the same building or cluster of buildings, such as a school.

A switch or hub is used to connect the devices to the network.

Devices on the network can connect wirelessly or, by cable and this allows a range of devices to be on a LAN at the same time.

A LAN may be connected to a WAN, for example computers within a school could be connected to the internet.

Question 3

What is a WAN?

Answer 3

A Wide Area Network (WAN) is a network in which the computers are geographically remote.

The computers in a WAN are connected by a telecommunications link, such as the public switched telephone network (PSTN).

A Wide Area Network is likely to be composed of several LANs connected together.

e.g. The internet and Bank ATMs are WANs

Question 4

Advantages of LAN

Answer 4

By using a local area network, computers can share peripherals such as printers and scanners. This reduces the cost of
buying and maintaining peripherals.

Networked computers typically require a username
and password from users who are authorised to
log onto the network. When an authorised user logs onto any computer on the network, they can access their own files, allowing flexible access from multiple locations.

Question 5

Disadvantages of LAN

Answer 5

The initial costs of purchasing and installing file servers, network cabling and peripherals can be expensive.

Depending on the size of the network, a member of staff may need to be hired and trained to act as a network manager.

By using a file server to store documents, users have flexible access but the disadvantage of this is that if the file server is damaged or breaks down, those files become inaccessible.

The organisation would also need to consider the security of their network as a virus could spread to all computers through the network.

Question 6

Advantages of WAN

Answer 6

Users have the capability of accessing a vast and diverse range of multimedia resources and services.

The benefits for organisations are on a global scale, as retailers can use e-commerce websites to sell their products to a worldwide market 24/7.

Users are able to use their access to manage bank accounts, shop online and communicate instantly with anyone who has similar access to the same Wide Area Network.

Question 7

Disadvantages of WAN

Answer 7

Some of the threats to a user or network include data theft, denial of service attacks and spamming.

There is also a danger of hacking as access to the internet can
potentially give outsiders access into a local area network.

Additional security is needed to prevent such attacks, for example by installing a firewall.

Question 8

What is a World Wide Web?

Answer 8

An application which runs on the internet. It is the most used service on the internet.

Pages on the World Wide Web are written in a programming language called HyperText Markup Language (HTML) and are viewed in a web browser (for example Internet Explorer or Safari).

The World Wide Web uses Hypertext Transfer Protocol to request and send web pages across the internet.

Question 9

What is the internet?

Answer 9

The Internet is the term used to describe the worldwide communications system that links computers, so it is the network that other applications like the World Wide Web use to function.

It is a collection of WANs

Question 10

What is the internet of things?

Answer 10

The Internet of Things is a term used to describe
the increasing number of devices and appliances
that are directly connected to the internet.

E.G. Smart home devices include systems to control lighting,
heating or appliances such as vacuums, security
cameras, ovens and fridge-freezers.

In the home, these devices can connect to a Wi-Fi network and
be monitored/ used remotely. Bluetooth can also be used for the same purpose.

Question 11

Advantage of Internet of Things

Answer 11

The main advantage of using devices such as these is an increased convenience for users, as they can monitor and control devices remotely or automate activities that they would previously have carried out manually

Question 12

Disadvantage of Internet of things

Answer 12

However, with the rapid expansion of appliances available on home and office networks, there is also an increased potential for hackers to attempt to access devices.

Question 13

What is an Intranet?

Answer 13

An intranet is a private communication network that can only be accessed from within a company or organisation.

Access is usually automatic using a single sign on when users are on site at the organisation, or users would use a username and password to access the intranet from remote sites.

It will include web pages used to share information that is relevant within the company.

It provides organisations with the facility to provide their staff
with information in a easily viewed format, which can be updated with key dates or announcements.

Question 14

Explain the term -
internet
World Wide Web
intranet
The Internet of Things

Answer 14

The internet is the network of interconnected networks which provides the communication links for data to be transferred between devices.

The World Wide Web is a service which uses the internet to transfer web pages between web servers and individual devices.

An intranet is a private network that only authorised users from an organisation can access.

The Internet of Things is the network of devices which have the capability to connect directly to the internet.

Question 15

What is WI-Fi?

Answer 15

Wi-Fi is a network technology that uses radio waves to allow a device (like a smartphone or laptop) to communicate with a wireless router. The router is connected to a hotspot which provides access to the internet.

Question 16

3 things which affect potential Wi-Fi output

Answer 16

Security Traffic Range

Question 17

Explain how security affects Wi-Fi

Answer 17

Wi-Fi routers can be configured to require a
password or can be made public for open access
by any Wi-Fi enabled device.

This can cause issues
with security if users are using an open Wi-Fi
network to share sensitive information such as
passwords or debit/credit card details.

Question 17

Explain how range affects Wi-Fi

Answer 17

The further away that a device is from the router, the weaker the radio signal will be.

As a result, the user might experience web pages or data downloading slower than expected.

Wi-Fi signal is affected by walls or doors being between the router and the device. In some cases, this can result in a black spot or dead spot, where there is an area within a house or office where the signal is too weak to access the Wi-Fi router.

This can be overcome by using a Wi-Fi repeater or extender, which will receive and repeat the radio signal from the original router to improve the range.

Question 18

Explain how traffic affects Wi-Fi

Answer 18

Wi-Fi uses radio technology, so the number of devices that can connect to the wireless network is dependent on the number of channels available on the wireless router.

Home routers will often have sufficient channels for the number of devices connecting to the network, but in a school or office setting a router may struggle to service a large number of laptops or tablets if they are all attempting to connect at the same time.

Question 19

Advantages of Wi-Fi

Answer 19

Flexible access, users can move around with their
device.

Organisations can allow open access for customers
or guests.

Cheaper than installing wide scale cabling.

Question 20

Disadvantages of Wi-Fi

Answer 20

Susceptible to security risks, particularly open Wi-Fi
networks.

Range is limited by the strength of the router and
the location they’re used in.

A large number of devices using the same router may cause service to slow down or stop.

Question 21

What is Bluetooth?

Answer 21

Bluetooth is a short range wireless communication standard. It is a radio technology and network protocol

A pair of devices both need to have Bluetooth capability enabled in order to communicate with each other.

Bluetooth is being integrated into a wide range of devices such as laptops, smartphones, portable speakers, headphones and smartwatches.

Question 22

Advantages of Bluetooth

Answer 22

Can be used to pair devices e.g. headphones,
activity tracker.

Can be used to increase safety e.g. driving with a
hands-free device.

Automatic sensing - devices that have been
separated will ‘pair’ once in range again.

Small power requirement.

Question 23

What is a network protocol?

Answer 23

A protocol is a set of rules for communicating between devices

Question 23

Disadvantages of Bluetooth

Answer 23

Short range, in most cases the signal will drop when
the devices are more than 10 metres apart.

Data transmission rate may be slower than other
wireless technologies.

Question 24

What is optical fibre?

Answer 24

Optical fibre is a very fine glass strand that allows rapid transmission of data, using light beams.

Many strands are grouped together to make a cable, so the cable can carry multiple data signals at the same time.

The main consumer application for optical fibre is by companies offering high bandwidth internet services for TV on demand and high speed internet access.

Question 25

Advantages of optical fibre?

Answer 25

Faster data transmission than copper wiring.

Data can travel further than using copper wiring.

Glass fibres do not corrode.

Large data capacity.

Can support carrying multiple services at the same
time, for example TV, telephone and broadband
could all use the same optical fibre cable.

Question 26

Disadvantages of optical fibre?

Answer 26

More expensive than copper wiring.

Optical fibre cannot carry power, whereas copper
cable can carry power and signal simultaneously.

If multiple services are being provided (e.g. TV,
telephone, internet) using the same cable and the
cable fails, all services are lost.

Question 27

What is mobile communications technology?

Answer 27

Mobile broadband is the delivery of an internet service using mobile phone technology.

It can refer to the use of mobile phone signals to connect a computer or mobile phone to the internet. Not all laptops or computers will have the necessary hardware built into them to connect to mobile networks, so instead they require a ‘dongle’ or a portable modem which plugs into the USB port of the device being used.

To connect a tablet to a mobile broadband network typically requires a SIM or micro-SIM. Similar to the use of mobile phones, the quality of the connection is influenced by the signal available.

Question 28

Explain 3G

Answer 28

Currently, 3G mobile phone signal is widely available. 3G stands for 3rd generation, as it is the 3rd generation of the transmission standards used to transfer data.

Transmission standards are continually being developed in order to provide faster speeds of access.

Question 29

Explain 4G

Answer 29

As a result 4G (4th generation) networks are becoming more common, allowing speeds closer to wired broadband connections

Question 30

Advantages of mobile communication technology

Answer 30

Flexible access, users can move around with their
device.

High speed transfers when using 4G.

Allows users access to mobile gaming, social media,
instant messaging and video calls.

4G gives users internet access at a similar speed to
Wi-Fi but with greater security.

4G is better at penetrating buildings, whereas 3G
coverage is unable in some structures.

Question 31

Explain 5G

Answer 31

It is projected that 5G standards will be developed and deployed in the next 10 years, in part to facilitate the increased connectivity required for the Internet of Things and cloud computing.

5G will provide significantly faster delivery than 4G. 5G will also address some of the disadvantages of current mobile communication, for example by reducing battery consumption and latency (the time delay while a page loads or app downloads).

Question 32

Disadvantages of mobile communication technology

Answer 32

Speeds are limited by the strength of the mobile signal, which may depend on location.

A user must pay for access, usually on a contract basis. Unlimited usage is expensive and other options will cap the usage at a pre-agreed download limit (e.g. 2GB, 4GB).

4G coverage is increasing but is not universal.

The frequencies used for 4G may be incompatible with networks in other countries, meaning that a device may have 4G capability in the user’s home country but not when travelling abroad.

High battery consumption.

Question 33

What is a Network Interface Card?

Answer 33

Any computer that is connected to the network by a cable must have a network interface card (NIC).

The card allows the computer and the file server to communicate with each other.

A network interface card will have a port for a network cable to be plugged into. Laptops will contain a wireless network interface card which will allow the laptop to connect wirelessly to a router but will often also have a port to allow a user to connect a network cable.

Question 34

What are Network cables?

Answer 34

Cables within a local area network are typically copper based. There are some different types e.g.

Coaxial cable (has two conductors, a central single strand and several strands braided together and wrapped around the central strand),

Twisted pair (insulated copper wires twisted together with an earth wire).

Question 35

What is a switch?

Answer 35

A switch or switched hub is a connection point for a group of computers. The computers will be connected to the switch using network cables and the switch will be connected to the file server.

The purpose of the switch is to organise communication between the file server and the computers on the network. When two computers are both connected to a switch, the computers can send data to each other through the switch.

Question 36

What is router?

Answer 36

A router is a sophisticated switched hub. It will hold information about the addresses of computers attached to the network and forwards data to the correct computers efficiently.

They are usually used as gateways where a LAN is connected to a larger network (e.g. the internet). When used as a gateway, a router will monitor traffic and can limit access for certain sites or users.

Question 37

What is a network topology?

Answer 37

A network topology is the theoretical arrangement
of the components of a network.

Question 38

Explain how the network topology Bus works?

Answer 38

A bus network has each of the devices connected directly to a main communications line, called a bus, along which signals are sent.

Twin cable, for example coaxial cable, is usually used as the bus.

The use of a bus network is suitable for small networks, as it is cost effective to implement on a small scale.

If the bus cable has to carry traffic for a large number of devices, the efficiency of the network will drop. An additional disadvantage is that the network is dependent on the bus cable, and a fault in it will cause the network to fail. This type of network is less secure than a star network, because each device has access to the bus, and data could be intercepted during transmission.

Question 39

Explain how the network topology Star works?

Answer 39

A star network has all the network components connected to one central computer, which is often used as the file server.

The computer at the centre of the star network is sometimes referred to as a hub, nexus or central node.

The network is therefore reliant on the central node, and if it malfunctions the whole network will fail.

Conversely, the advantage is that if one of the computers is not working, the rest will not be affected.

This network is more expensive to install than a ring network because it usually requires more cabling and a file server capable of servicing the network requests from each computer.

Question 40

Explain how the network topology Ring works?

Answer 40

A ring network has each of the devices on the network connected to a ring communications line around which signals are sent.

This type of network can be implemented in two ways.

Traffic around the network can pass through the network interface of each device, which may require that all devices are functional for traffic to flow.

Alternatively, the network devices can be connected to the central ring by spurs, which allows the system to continue to work even when some devices are not switched on.

Question 41

Advantages of using a network

Answer 41

By using a network, it is possible to share peripheral devices such as printers and scanners.

In addition to being more environmentally friendly, this helps to reduce costs.

Users can access their files from any workstation, allowing flexible working environments.

The users of a network allows users to communicate easily using a variety of methods including email, instant messaging and video conferencing.

A network that runs using a file server has the benefit of providing the users with a central back-up of all files. Use of a file server provides a level of security by ensuring that users access their own files when they log on, but not files belonging to other users.

Networks centralise some of the processes carried out within an organisation, for example virus protection can be managed consistently rather than on each individual computer or device.

Question 42

Disadvantages of using a network

Answer 42

The initial costs of installing a network for an organisation can be high, as it might require the purchase of cabling and at least one file server.

The running costs can also be high for large networks.

the organisation may decide that they require a network manager to ensure the smooth and efficient use of the network resources.

The reliance on a file server to provide access to software and files could mean that a failure in the server will result in widespread breakdown. For this reason, in large networks, multiple servers are used and may be housed in separate parts of a building.

While efforts can be made to secure a network against viruses, a breach could give a virus or hacker access across other computers. Procedures can be put in place to help minimise these risks, for example, the use of a firewall.