2. Networks Flashcards
(192 cards)
1
Q
What is a network
A
two or more devices that have been connected to each other.
2
Q
Name network components
A
1.Network interface card (NIC)
2.Hub
3.Switch
4.Router
5.Modem
6.Gateway
7.Bridge
8.Repeater
9.Server
10.Wireless access point (WAP)
3
Q
Define NIC
A
a piece of hardware
that is built into a device:
allows it to have a wired on
wireless connection
The main component that any device needs to connect to a network
4
Q
What type of connection does a basic NIC support?
A
A wired connection.
5
Q
Define ethernet
A
a protocol used
to connect devices in a LAN
using a wired connection
6
Q
Define a hub
A
network hardware that devices connect to so that they can send data to
each other in a network
A hub is the most basic way of
connecting several devices in a
local area network (LAN).What
7
Q
What is LAN
A
a type of network that is
normally located within a
single building or site
8
Q
What is the function of the hub
A
A hub receives data packets and
forwards them on to all devices
that are connected to the hub.
Only the intended destination device
will accept the data sent; the other
devices connected to the hub
will just ignore it
9
Q
Define data packet
A
the unit of data that contains the information to be transmitted across
a network
10
Q
What types of wired connections are normally used with a hub?
A
Ethernet or USB connections.
11
Q
What is a major drawback of using a hub in a network?
A
It creates a lot of unnecessary traffic, leading to data collisions and reduced performance.
12
Q
Define data collision
A
when two devices on a network send
data simultaneously the data packets can collide
13
Q
What is a switch
A
network hardware that reads MAC addresses
to send data to the correct device
14
Q
What is a media access control
(MAC) address:
A
a unique address that is given to the NIC in each device at the point of manufacture
15
Q
What is the main function of a switch in a LAN?
A
To connect several devices and send data only to the intended destination device.
16
Q
What is the key difference between a switch and a hub?
A
A hub sends data to all devices, while a switch sends it only to the intended device.
17
Q
How does using a switch improve network performance?
A
It reduces network traffic and data collisions.
18
Q
Define an router
A
network hardware that reads IP addresses to
send data to the correct network or device
19
Q
How does the router transfer data
A
It uses a special database called a routing table to send data packets along the correct route to their intended destination.
It does this by reading the internet protocol (IP) address of the destination device that is stored in the data packet.
It then sends the data packet towards the destination address and selects the most suitable route for it to take
20
Q
Define a modem
A
network hardware that converts between
analogue and digital signals
21
Q
What is the primary function of a modem?
A
To convert analogue signals to digital and vice versa.
22
Q
Why is a modem necessary for internet communication over telephone lines?
A
Because it converts analogue signals from the phone line into digital signals a device can process.
23
Q
Define a gateway
A
network hardware that acts as a
translator between the two networks, converting
data from one protocol to another to allow the
networks to communicate with each other
24
Q
What is the function of a gateway in networking?
A
To connect one LAN to another LAN or to a WAN.
25
Whats a WAN
a type of network
that is normally spread
across several buildings or
sites;
26
How does a gateway help networks with different protocols?
It acts as a translator, converting data from one protocol to another
27
Define a bridge
network hardware
that is used to connect one
LAN to another LAN
28
What is the purpose of a bridge in networking?
To connect one LAN to another LAN, creating a larger LAN.
29
Why use a bridge instead of one large LAN?
Because LANs might be too far apart to function effectively as a single LA
30
How does a bridge operate similarly to a switch?
it reads the MAC address of a device from the data packet and forwards it to the correct destination.
31
Define a repeater
a network device that is used to boost the
strength of an electrical signal
32
What is the function of a repeater in a network?
To boost the strength of an electrical signal so it can travel farther.
33
What else can a repeater do besides boosting signal strength?
It can reconstruct a distorted electrical signal.
34
What is a server
a central device in a network that stores
data and can also provide services;
it accepts and responds to requests that
are made for different types of data
35
What is the main function of a server in a network?
To accept and respond to requests for data or services.
36
What is a common example of a server?
A web server.
37
What are some services that servers can provide?
Storing files, managing printing jobs, and handling web page requests.
38
Define wireless access point
(WAP):
network hardware
that transmits and receives
radio wave signals
39
What is used to create a wireless connection point for devices with a WNIC?
A wireless access point (WAP).
40
What role must all routers be set up to perform?
All routers must be set up to act as a gateway.
41
NETWORK TRANSMISSION MEDIA
What are the Types of wired connections
twisted pair cable
coaxial cable
fibre optic cable
powerline.
42
What are the types of wireless connections
microwave
radio wave
light
satellite.
43
Define twisted pair cable
a copper cable that has two twisted wires: it can
be used to transmit data across a network
44
characteristics of twisted pair cables.
1. can be unshielded or shielded.
2. transmit data using electrical currents.
3. transmit data up to a speed of 10 Gbps.
4. cheap to manufacture.
5. suffer from electromagnetic interference, only used to carry data over short distances.
6. They are easy to install.
45
Define coaxial cable:
a single central wire with insulating
layers:
it can be used to transmit data across a network
46
What are Twisted pair cable used for
used for telephone communications and for ethernet connections in a local area network within one building.
47
characteristics of coaxial cables.
1. transmit data using radio frequency signals.
2. transmit data at speeds of up to 10 Mbps.
3. cheap to manufacture, but not as cheap as twisted pair cables.
4. less prone to electromagnetic interference because of the braided metal conductor layer.
5. difficult to install, as they can be stiff and difficult to bend.
48
What are Coaxial cable used for
in cable TV connections and sometimes in internet connections.
49
Define Fibre optic cable
a cable
that is made up of fine
strands of glass or plastic
50
characteristics of fibre optic cables.
1. transmit data using light.
2. transmit data up to speeds of 1 Gbps.
3. expensive to manufacture
4. not prone to electromagnetic interference.
5. difficult to install, as the cables can be fragile.
51
What are fibre optic cables used for
internet connection and transmitting data over long distances.
52
define powerline:
a device that
plugs into a power socket
and transmits data over the
electrical wiring to another
device on the same circuit
53
characteristics of powerline connections.
1. transmit data using electrical wiring.
2. transmit data at speeds of up to 2 Gbps.
3. relatively expensive to manufacture.
4. prone to electromagnetic interference and are limited by the condition of the electrical wiring in the building.
5. very easy to install, as they can be simply plugged into any electrical socket.
54
What are powerline connections used for
large houses and buildings to allow data to travel more effectively over a longer distance.
This can include extending an internet connection to an area that gets poor coverage in a house.
55
How do microwaves travel between technologies?
Microwaves are point-to-point and travel in a straight line.
56
What are microwaves?
Microwaves are electromagnetic waves used to create a wireless connection between technologies
57
What is the frequency range of microwaves?
Between 1 GHz and 300 GHz.
58
Why are microwaves normally used for short-distance data transmission?
Because they are high-frequency waves with short wavelengths and require a direct line of sight.
59
when are microwaves used
for communication between cell phone towers?
A: Microwaves.
60
What are radio waves?
electromagnetic radiation
that can be used to create
a wireless connection in
a network
61
How do radio waves travel?
Radio waves are omnidirectional, traveling in all directions without needing a line of sight.
62
What is the frequency range of radio waves?
3 kHz to 1 GHz.
63
How do radio waves compare to microwaves in terms of frequency and wavelength?
adio waves have a lower frequency and a longer wavelength than microwaves.
64
What technology commonly uses radio waves for communication?
Wireless LAN networks.
65
What is infrared light:
electromagnetic radiation
with wavelengths longer
than visible light but
shorter than radio waves
66
How is infrared light transmitted between devices?
A beam of infrared light is directed through the air and requires a direct line of sight.
67
What is an example of using infrared to connect devices?
Connecting peripheral devices like a keyboard and mouse to a computer.
68
Why is infrared not a popular method for connecting devices?
Because the infrared signal is weak and requires a direct line of sight between devices.
69
What is a satellite
a device that
orbits the Earth and uses
radio waves to transmit
data
70
What type of waves do satellites use to transmit data?
Radio waves.
71
What is a ground station?
A base on Earth that transmits and receives radio waves to and from a satellite.
72
What is the most common use of satellite communications?
Global Positioning Systems (GPS).
73
four main ways that a network can be structured:
client-server network
peer-to-peer network
ad hoc network
tethering.
74
What is client-server network:
a type of network that has central servers working
as a point of control in the network and client
computers that connect to them
75
Benefits of client-server network:
1. Security for the network can be carried out by a server.
(Each user does not need to be solely responsible for this.)
2. Updates for any software can be carried
out by a server.
( Each user does not need to
update their own computer. An organisation can be sure that everyone is using the same version of software. This can help avoid compatibility issues.)
3. A backup of all files can be created from the data stored on the server.
(Each user does not need to remember to back up their own files.)
4. If a client computer crashes, it will not affect the rest of the network.
(The user will also be able to use another client computer in the network and access all the data and
resources they were using.)
76
Drawbacks client-server network:
1. A server is an expensive piece of technology to buy.
( A client-server network can need several
servers, so it can be expensive to set up.)
2. The network will need specialist technicians to maintain the servers and the network
.
3. If a server fails then the users of the client
computers in the network will not be able to
access the resources and services provided
by that server.
77
define peer-to-peer network
а type of network that does
not have a server as a point of control;
all devices
on a peer-to-peer network
are equal
78
Give an example of a simple peer-to-peer network.
A mobile phone connected to a computer.
79
Benefits peer-to-peer network.
1. Each peer computer can share files and resources.
.
2. It is cheap to set up as it just needs transmission media to connect the computers. No expensive servers need to be purchased.
3. does not require any specialist technicians therefore also cheap to maintain.
4. If one peer computer fails, it will only be the public files and resources stored on that computer that will be unavailable to other users.
80
Drawbacks of peer-to-peer network.
1. The network is less secure than a client-server network. as each user is responsible for the security of their own computer and data.
2. Each user is responsible for backing up their own data.
3. If too many peer computers are added to the network, the volume of network traffic can slow down the network.
81
What is an ad hoc network?
a temporary network that is set up to share resources
82
Why are ad hoc networks typically set up?
To temporarily share resources, such as files, when other network components are not available.
83
How does a student set up an ad hoc network in the example provided?
The student sets up the network by transmitting their network ID and listening for devices that want to connect.
84
Benefits of ad hoc networks
1. The network can be set up anywhere as it
does not require any special components
2. It is cheap to set up the network as no new network components need to be purchased.
85
Drawbacks of ad hoc networks
1. Security can be weaker in this type of
network.
This is because the connection is
created wirelessly and anyone close by could try to connect.
2. If the ad hoc network becomes too large it ( data collisions and data loss)
3. Not all devices are able to connect to an ad hoc network.
Some portable devices such as mobile phones may not have a setting to
allow them to do this.
86
What is tethering?
the process of
connecting another device
to a mobile phone to make
use of the phone's internet
connection
87
What does tethering turn a mobile phone into?
A hotspot, which can be considered a portable router.
88
What types of connections can be used for tethering?
Wi-Fi
Bluetooth
USB.
89
Benefits of tethering?
1. Any device can be given an internet
connection, even when a Wi-Fi network is
not available.
2. save on costs as only the mobile phone
needs a data plan.
3. Tethering can be more secure than using
a public Wi-Fi connection, as the network
created is a private network.
90
Drawbacks of tethering?
1. Tethering can drain the battery of the devices,
2. Tethering will use the data in the data plan for the mobile phone. Streaming video or downloading large files could use up a lot of the data
3. It is essential to set a strong password for the tethered connection. .
91
What are the main network metrics
1. Speed
2. Bandwidth
3. Throughput
4. Scalability
5. Latency
6. Error rate
7. Packet loss
8. Availability
9. Jitter
92
What is speed
the speed at which the data is transferred from
one device to another
93
What is bandwidth?
the maximum amount of data that can be transferred from one device to another in a set
amount of time
94
What does a higher bandwidth usually mean for network speed?
A higher bandwidth typically means faster network speeds.
95
How does the number of devices on a network affect bandwidth?
The available bandwidth is shared between the devices, so more devices on the network will result in slower data transfer speeds.
96
What is throughput?
the amount of data that actually passes through the network from one device to another in a set amount of time
97
What is Scalability
how well the capacity of a network can be increased or decreased to respond to different amounts of data transfer
98
How can a network be made scalable?
By being able to increase its bandwidth when necessary.
What is latency
99
What is latency
the delay that can be present in the transmission of data across the network
100
What is the error rate
a measure of the number of errors that occur in a network
101
What types of errors are measured in a network's error rate?
Data packet loss, data packet corruption, and data collisions.
102
What is packet loss
a measure of the number of packets that were transmitted from the sending device but did not arrive at the receiving device
103
What is Availability
a measure of the amount of time a network is available for use
104
What is jitter
a measure of the disruption that occurs when data is transmitted across a network
105
What causes jitter in a network?
by network congestion, latency, or network errors.
106
What is a protocol
a set of rules that
govern the transmission of
data in a network
107
Which organization regulates most networking protocols?
the Institute of Electrical and Electronics Engineers (IEEE).
108
types of communication protocols
ethernet
Wi-Fi
Bluetooth
ZigBee
cellular
infrared.
109
What is Ethernet?
a protocol used to connect devices in a LAN using a wired connection.
110
What types of cables are used in Ethernet connections?
coaxial, twisted pair, or fiber optic.
111
how fast can Ethernet transfer data today?
reach speeds of up to 100 Gbps.
112
benefits of Ethernet
1. cheap to buy (low manufacturing costs)
2. more secure than a wireless connection
reliable; it uses error detection methods to detect any errors in data transmission
3. compatible with many devices that require a wired connection to a network;
4. easy to install; it only requires an ethernet cable to be plugged into an ethernet port.
113
How does Wi-Fi transmit data?
Wi-Fi transmits data using radio waves.
114
What is Wi-Fi?
a type of wireless data transmission that uses radio waves to transmit data
115
What are the two frequencies that Wi-Fi can use to transmit data?
2.4 GHz and 5 GHz.
116
What is Bluetooth?
a type of wireless data transmission that uses radio waves to transmit data between two devices that are in close range (within 10 m)
117
How do devices connect using Bluetooth?
Devices connect using a system called pairing, where the host device (e.g., smartphone) scans for compatible devices, and the user selects the device to pair with.
118
What is the maximum data transfer speed for a Bluetooth connection?
Bluetooth can transfer data at speeds of up to 3 Mbps.
119
: What is ZigBee?
type of wireless data transmission that uses
radio waves to transmitmdata between two devices:
120
How is ZigBee different from Bluetooth?
ZigBee is used to connect different types of devices, such as smart light bulbs to virtual assistant technology, whereas Bluetooth is used to connect devices like smartphones to wireless headphones or car entertainment systems.
121
What is the maximum range of a ZigBee connection?
ZigBee has a range of up to 100 meters.
122
What is a cellular network:
a type of network made up of cells that each have a base station that is used to transmit signals used by mobile phones
123
What types of electromagnetic waves are used in a cellular network?
Radio waves and microwaves.
124
How are radio waves and microwaves used differently in cellular networks?
Radio waves transmit data from a phone to a base station; microwaves transmit data between base stations.
125
What is GSM?
GSM (Global System for Mobile Communications) is a set of protocols used to transmit data across cellular networks.
126
What are the set of protocols that are used to govern the transmission of data across
a network:
1. open systems interconnection (OSI) model
2. transmission control protocol/internet protocol (TCP/IP)
3. voice over internet protocol (VOIP)
4. session initiation protocol (SIP).
127
What is the OSI model?
A theoretical framework developed in 1984 to structure the transmission of data across a network.
128
What is the main concept behind the OSI model?
It divides the protocol into layers, each with a specific function.
129
What are the seven layers of the OSI model.
Application
Presentation
Session
Transport
Network
Data link
Physical
130
What does the Application Layer do?
It directly interacts with user data, receives data from the user, and displays data for the user.
131
what are the software applications that are part of the Application Layer?
web browsers and email
clients
132
What are examples of protocols provided by the Application Layer?
Hypertext Transfer Protocol (HTTP) and File Transfer Protocol (FTP).
133
What does the Presentation Layer do in the OSI model?
It prepares data for use in the Application Layer.
134
How does the Presentation Layer prepare data?
By encoding, encrypting, or compressing the data.
135
Why is the Presentation Layer important?
It ensures that data is in the correct format for the intended device.
136
What is the role of the session layer
The role of this layer of the framework is to create channels of communication (called sessions) between devices.
It is responsible for opening a session, making sure it's open on for long enough to transmit the data, then closing the session.
137
What is the main function of the Transport Layer in the OSI model?
It breaks data into segments for transmission and reassembles them after transmission.
138
What additional responsibilities does the Transport Layer have?
It sends data at an appropriate network speed, checks for errors, and requests re-sending of data if errors are found.
139
What additional role does the Network Layer perform?
It finds the best route for packets to travel across networks, usually with the help of a router.
140
What is the main function of the Network Layer in the OSI model?
It breaks down segments into packets and reassembles packets back into segments.
141
What is the main role of the Data Link Layer in the OSI model?
It transmits data within a single network by converting packets into frames.
142
What are the two sublayers of the Data Link Layer?
Logical Link Control (LLC) and Media Access Control (MAC).
143
What does the Logical Link Control (LLC) sublayer do?
It manages protocols and handles error checking.
144
What does the Media Access Control (MAC) sublayer do?
It uses MAC addresses to connect devices.
145
What is the purpose of the physical layer
This layer is all the wired cables or wireless connections that are made between the devices in the network.
The data is broken down into bits for
the layer so that it can be transmitted down a cable or across rad
146
What is a TCP/IP model:
a protocol that is used to transmit
data across the internet and it has the 4 layers Application layer, Transport layer, Network/internet layer , Link/physical layer
147
the TCP/IP layers and the description
Application layer- This layer incorporates the role of the application, presentation and
session layers from the OSI model.
Transport layer- This layer is the same as the transport layer in the OSI model. It
uses the transmission control protocol (TCP).
Network/internet layer- This layer is the same as the network layer in the OSI model. It uses the internet protocol (IР).
Link/physical layer- This layer incorporates the role of the data link layer and the
physical layer from the OSI model.
148
Difference between TCP/IP and OSI model
* OSI is about communications between a network and a user
* TCP/IP is about connecting hosts over the internet/a network
* OSI is generic/protocol independent / can use any appropriate protocol
* TCP/IP is based on (standard) internet protocols
* OSI is a reference model/guide
* TCP/IP is an implementation of that (OSI) model
149
What is VOIP?
a protocol that is used to send data when
one person is making a voice call to another person using the internet
150
What devices commonly use VOIP for making calls?
PCs and laptops.
151
Why was VOIP developed?
To allow people to use devices other than mobile phones to make calls.
152
What additional protocol is involved with VOIP?
SIP (Session Initiation Protocol).
153
What layer of the OSI model does SIP operate in?
The Application Layer.
154
Each device that is part of a network also has an address. What are they
a MAC address
an IP address
155
What is a MAC address
A MAC address can be used to identify a device in a network.
The MAC address is assigned by
the manufacturer of the device when it is being made.
The MAC address is actually given to the
NIC that is built into the device
156
features of MAC address
1. Each address is unique.
2. written in hexadecimal
3. It has 12 digits and the digits are grouped
in pairs.
4. Each pair of digits is separated by a colon.
5. The first three pairs of digits are the
manufacturer's ID.
6. The second three pairs are the serial
number of the device.
157
What can an IP address be used for in a network?
To identify a device.
158
How is an IP address usually assigned in a home network?
Automatically by the router.
159
features of IP address
1. Each address is unique to the network that the device is connected to.
2. It can be static or dynamic.
3. There are two different versions of IP addresses - IPv4 and IPv6.
160
What is a static IP address
A static address means the device will always have the same IP address.
161
What is dynamic IP address
A dynamic address means the IP address of a device can change each time it connects to a network.
162
differences between IPv4 and IPv6.
look at page 36 of text book
163
two main threats that a device can be exposed
people who want to hack the device to steal the data stored on it
people who want to install malware on the device to corrupt the data stored on it.
164
Security solutions to help protect data
Authentication
Security settings
Access rights
Anti-malware
Firewall
Physical controls
Encryption
165
Define Authentication
a collection of security methods that are used to verify the identity of a user when they are trying to access a device or an
account
166
What is two-factor authentication (2FA)?
A method that requires a second verification from the user.
167
What are the three main types of
authentication.
Password
Two-factor
Biometrics
168
How is the second verification usually delivered in 2FA?
As a numeric code sent to the user's device.
169
Where is two-factor authentication commonly used?
In online banking.
170
What types of biological data can be used in biometrics?
Fingerprints, facial features, iris patterns, and voice recognition.
171
Define Security settings
ways that a user can control who
can see or access data that they store in an account
172
Define Access rights
restrictions
that are placed on who can
see and edit data
173
What are access rights designed to do?
Limit the data a hacker or user can see and edit.
174
What happens when a user logs in regarding access rights?
The network server checks their username to determine what data they can see and what actions they can perform.
175
How do access rights improve security if a hacker gains access?
The hacker might not be able to see or edit all the organisation’s data.
176
What is malware?
Malicious software designed to damage a device or the data stored on it.
177
What are some common examples of malware?
Viruses, spyware, trojan horses, and ransomware.
178
How is malware usually installed on a device?
By unknowingly downloading a malware-infected file from the internet.
179
What is anti-malware
software that scans a device and removes or quarantines malware
180
How does anti-malware help protect a device?
By detecting, isolating, and removing malware threats.
181
Why is it important to regularly update anti-malware software?
Because new malware is constantly being created, and updates help the software recognize the latest threats.
182
Where is a firewall
a type of security
setting that can be used to
examine data incoming and
outgoing from a computer
or network
183
What are the two types of firewalls?
Hardware firewall and software firewall.
184
Difference between Hardware firewall and software firewall.
A hardware firewall is a separate device that is placed between the computer and the network.
A software firewall is software that is installed
onto the computer.
185
What does a firewall do?
It examines all incoming and outgoing data traffic against a set of criteria.
186
How does a firewall help protect devices?
By blocking hackers and malware based on set criteria.
187
Define physical controls
physical security measures
that can be used to keep
data secure, such as CCTV
and locks on doors
188
What is encryption?
a method of
security that scrambles
data to make it
meaningless
189
What is used to encrypt data?
An algorithm called an encryption key.
190
What are the two types of encryption?
Symmetric and asymmetric encryption.
191
How does symmetric encryption work?
It uses the same key to encrypt and decrypt data.
192
How does asymmetric encryption work?
It uses different keys to encrypt and decrypt data.
