Unit 1.5 - Network topologies, protocols and layers

Question 1

Topology

Answer 1

Diagram showing the Layout of connections in a network

Question 2

Features - Star Topology

Answer 2

Computers connected to a

central switch in a LAN

Question 3

Advantages - Star Topology

Answer 3

Reliable
No Data Collisions
High Performance
Easy to Add/Remove Nodes

Question 4

Disadvantages - Star Topology

Answer 4

Expensive - Cables
Extra Hardware - Switches
Server/Switch Fails - connected nodes fail

Question 5

Features - Mesh Topology

Answer 5

Switches/Routers connected so more than one possible route

Question 6

Advantages - Mesh Topology

Answer 6

Reliable & Self-Healing
High Performance- Data sent same time, No Collisions, High Traffic
No Central Node

Question 7

Disadvantages - Mesh Topology

Answer 7

Expensive & Difficult - Cables

Redundant Connections

Question 8

Uses - Mesh Topology

Answer 8

Cluster of Surveillance Drones

Military Communications

Smart Devices around the home

Question 9

Features - Ring Topology

Answer 9

Device connect to two others in ring. Data Travels in one Direction

Question 10

Advantages - Ring Topology

Answer 10

No Data Collisions

Question 11

Disadvantages - Ring Topology

Answer 11

Cable/Device fail - Network fail

Low Performance

Question 12

Features - Bus Topology

Answer 12

One Main cable.

Terminators - stop signals reflecting back

Question 13

Advantages - Bus Topology

Answer 13

Easy to install

Low Cost - Cable

Question 14

Disadvantages - Bus Topology

Answer 14

Cable fail - Network fail
Data Collisions
Low Performance
Security Risks - All devices see all data

Question 15

Wi-Fi

Answer 15

Wireless connection to Network

Requires a WAP / Router.

Data sent on specific frequency called a channel

Question 16

Advantages - Wi-Fi

Answer 16

Convenient & Low Cost

No Cables - Wander around

Add/Remove Devices easily

Less Disruption to Building/Walls

Question 17

Disadvantages - Wi-Fi

Answer 17

Interference & Signal quality

Less Secure - Hacking

Lower Bandwidth than wired

Question 18

Wi-Fi - Frequency

Answer 18

2.4 Ghz

5 Ghz

Question 19

Features - 2.4 Ghz

Answer 19

Long range
Slow data transmission
(450 Mbps or 600 Mbps)
Interference from Cordless phones, baby monitors

Question 20

Features - 5 Ghz

Answer 20

Short range
Fast data transmission
(1300 Mbps)

Question 21

Wi-Fi - Channels

Answer 21

Channels 1 - 11

Used for Radio Wave Communication

Interference
Cordless phones, baby monitors.

Question 22

Wi-Fi - Encryption

Answer 22

Data is Scrambled
during communication

Protect from Hackers, unreadable if intercepted.

Recipient needs Key to decode

Question 23

Wi-Fi - Protocols

Answer 23

Set of rules for how computers communicate (send/receive data)

Speed of transmission, size of the message, error checking, transmission

Question 24

TCP/IP

Answer 24

Transmission Control Protocol/Internet Protocol

TCP Provides Error Free Transmission Separates & Reassembles data packets

IP routes packet across a WAN giving the packet its destination address.

Question 25

HTTP

Answer 25

Hyper-Text Transfer Protocol Allows the browser to communicate with a web server to request and deliver HTML Web Pages

Question 26

HTTPS

Answer 26

Hyper-Text Transfer Protocol Secure Encrypts connection/data

Question 27

FTP

Answer 27

File Transfer Protocol Transmit files between client & server

Question 28

POP

Answer 28

Post Office Protocol Allows Email Clients to retrieve and delete email from an email server

Question 29

IMAP

Answer 29

Internet Message Access Protocol Allows Email Clients to retrieve email from an email server (not deleted).

Question 30

SMTP

Answer 30

Simple Mail Transfer Protocol Send emails to Email Server

Question 31

Layers

Answer 31

Reduces the complexity of networking into smaller manageable sub-problems

Question 32

Layers - Application (7)

Answer 32

APPLICATION you are using

Question 33

Layers - Presentation (6)

Answer 33

ENCRYPT / FORMATS / TRANSLATE / COMPRESS | the data

Question 34

Layers - Session (5)

Answer 34

CONNECTIONS are established, managed, and torn down when communicating on a LAN (Same network)

Question 35

Layers - Transport (4)

Answer 35

CREATING, SEQUENCING, ERROR CHECKING packets When communicating on a WAN (Different networks).

Question 36

Layers - Network (3)

Answer 36

ROUTING PACKETS on a WAN (Different networks)

Question 37

Layers - Data Link (2)

Answer 37

CREATING, ROUTING, ERROR CHECKING frames When communicating on a LAN (Same networks)

Question 38

Layers - Physical (1)

Answer 38

DATA ENCODING bits (0/1).

Question 39

Data Packet

Answer 39

A unit of data transmitted across a network. TCP splits Large Files down into small packets

Question 40

Data Packet - Header

Answer 40

``` Contains: IP address Packet number Length of packet Protocol used ```

Question 41

Data Packet - Payload

Answer 41

Contains: | The Data

Question 42

Data Packet - Trailer

Answer 42

Contains: End-of-packet marker Error checking (Check sum)

Question 43

Packet Switching - Frame

Answer 43

Unit of data transmitted between two locations on LAN

Question 44

Packet Switching

Answer 44

Sending data packets across a network. | Each packet finds its own route and reassembled at destination

Question 45

Circuit Switching

Answer 45

Link is established first Packets sent in a stream along the established connection until received

Question 46

Data Collisions

Answer 46

2 devices transmit data on the same network at the same time down the same connection

Question 47

Packet Sniffing

Answer 47

Captures a copy of packets of data for reading / analyzing