Fundamentals of Communication and Networking

Question 1

Bandwidth

Answer 1

The range of frequencies that a communication medium is capable of transmitting

Question 2

Latency

Answer 2

The difference in time of an action being initiated and its effect being noticed

Question 3

Protocol

Answer 3

A set of rules for communication between devices

Question 4

Serial Data Transmission

Answer 4

Data is transmitted through a communication line one bit at a time

Question 5

Parallel Data Transmission

Answer 5

Uses multiple parallel communication lines to send multiple bits simultaneously

Question 6

Skew

Answer 6

When bits that are sent together may not be received together

Question 7

Crosstalk

Answer 7

When signals leak from one line into another which causes data corruption

Question 8

Synchronous Transmission

Answer 8

When data is sent between devices who have their clock speed’s synchronised so data is received in the same order they were sent

Question 9

Asynchronous Transmission

Answer 9

Uses start and stop bits on either side of the transmission in order time the clock signals of the communicating devices

Question 10

Topology

Answer 10

The structure of a network

Question 11

Star Topology

Answer 11

Network structure where there is a central switch where all client are directly connected to

Question 12

Bus Topology

Answer 12

Network structure where there is a single cable (backbone) which every client is connected to

Question 13

Client-server Networking

Answer 13

Type of network where clients are connected to one or more central servers which allow the clients to access all resources

Question 14

Peer-to-peer Networking

Answer 14

Type of network where all clients together act as a server to perform and share resources but certain ones are lost when clients are switched off

Question 15

Service Set Identifier (SSID)

Answer 15

Name that identifies a wireless network

Question 16

Media Access Control (MAC)

Answer 16

Unique addresses are assigned to every wireless device by the manufacturer

Question 17

Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)

Answer 17

Protocol used in wireless networks to avoid data collisions when multiple devices are communicating by listening to communication channel and sending data if it’s idle, if not, it waits a random period of time

Question 18

Request to Send/Clear to Send (RTS/CTS)

Answer 18

This is added on to CSMA/CA to avoid hidden nodes by checking whether the network is idle

Question 19

The Internet

Answer 19

Network of interconnected computer networks

Question 20

Internet Service Provider (ISP)

Answer 20

Company which provides their customers access to the internet

Question 21

Packet

Answer 21

Container in which data is sent over networks

Question 22

Packet Switching

Answer 22

Data transmission where data is broken into packets which are sent across the internet via optimum routes and are then reassembled at the destination

Question 23

Primary Components of a Packet

Answer 23

Sender’s address
Recipient’s address
Time To Live (TTL) - Number of hops a packet can do before being dropped
Packet contents
Sequence number

Question 24

Router

Answer 24

Network device that forwards data packets between computer networks

Question 25

Gateway

Answer 25

A computer which that sits between different networks or applications

Question 26

Uniform Resource Locator (URL)

Answer 26

An address which is assigned to files on the internet

Question 27

Parts of the URL (7)

Answer 27

Protocol Subdomain (www) Domain - Name of the organisation Directory of file being requested (e.g. /news) Subdirector of file being requested (e.g. /technology) Name of file being requested (e.g. /index) File's extention (e.g. html)

Question 28

Domain Name

Answer 28

Identifies an organisation or individual on the internet

Question 29

Domain Name System (DNS)

Answer 29

Turns domain names into IP addresses which allows browsers to get to the websites

Question 30

Firewall

Answer 30

Sits between the internet and the device and regulates the packets that pass through, can perform packet filtering and stateful inspection

Question 31

Packet Filtering

Answer 31

Can accept and block certain packets based on source IP address or protocol they are using

Question 32

Stateful Inspection

Answer 32

Examines the contents of the packets before allowing it through the firewall

Question 33

Proxy Server

Answer 33

Sits between a public and private network, regulating all the packets that pass through

Question 34

Symmetric Encryption

Answer 34

Both the sender and receiver have the same private key to encrypt and decrypt data send between the two parties

Question 35

Asymmetric Encryption

Answer 35

Four keys are used in encryption/decryption as there is a public key in which the data is encrypted but only the private key can decrypt it and vice versa

Question 36

Digital Signatures

Answer 36

These are used for asymmetric encryption to verify the sender of the data and whether the data has been tampered with

Question 37

Digital Certificate

Answer 37

Verifies the ownership of a key pair (public and private key) during asymmetric encryption

Question 38

Worms

Answer 38

Type of malicious software which can automatically self-replicate and infect other devices on the network

Question 39

Trojans

Answer 39

Type of malicious software that is disguised as a safe/legit file but contains malware when opened or downloaded

Question 40

Viruses

Answer 40

Type of malicious software that attaches itself to programs or files so it can replicate and spread through the computer

Question 41

TCP/IP model

Answer 41

Defines how devices should transmit data between then and enables communication over a large distance

Question 42

Application Layer

Answer 42

Layer of the TCP/IP model which determines which protocol to use for communication and provides the interfaces needed by the user

Question 43

Transport Layer

Answer 43

Layer of the TCP/IP model which splits up the data into packets, containing their sequence number and what they consist of and ensures error-free, end-to-end delivery of data

Question 44

Network Layer

Answer 44

Layer of the TCP/IP model which handles the routing and sender of the packets across networks

Question 45

Link Layer

Answer 45

Layer of the TCP/IP model which facilitates the transmission of the packets across a network (physical layer) to reach the destination MAC address

Question 46

Structure of IPv4 address

Answer 46

Network identifier - What network it is on (3 bytes) Host identifier - What PC in that network (1 byte)

Question 47

Subnet Mask

Answer 47

Sequence of binary digits, 1s are repeated until the network identifier has been shown. Mask is ANDed with IP address

Question 48

IPv4 address

Answer 48

32 bits

Question 49

IPv6

Answer 49

128 bits

Question 50

Routable IP address

Answer 50

Uniquely assigned to devices which are directly connected to public/global internet

Question 51

Who are Routable IP addresses assigned by?

Answer 51

Global organisations like IANA

Question 52

Non-Routable IP Addresses

Answer 52

(PRIVATE) - Assigned to devices on a private network

Question 53

Network Address Translation (NAT)

Answer 53

Converts IP addresses as they get transferred between public and private address spaces (Router)

Question 54

Port Number for HTTP

Answer 54

80 and 8080

Question 55

Port Number for FTP

Answer 55

20

Question 56

Port Number for POP3

Answer 56

110

Question 57

Port

Answer 57

Allows the TCP/IP protocol to decide which application should deal with the packet when it arrives

Question 58

Dynamic Host Configuration Protocol (DHCP)

Answer 58

A DHCP server is a device which is responsible for automatically assigning a dynamic IP address from a pool of available addresses to computers which operate on a private or public network