Unit 1.5 - Network topologies, protocols and layers Flashcards Preview

OCR GCSE 2019 COMPUTER SCIENCE > Unit 1.5 - Network topologies, protocols and layers > Flashcards

Flashcards in Unit 1.5 - Network topologies, protocols and layers Deck (47)
Loading flashcards...
1

Topology

Diagram showing the Layout of connections in a network

2

Features - Star Topology

Computers connected to a
central switch in a LAN

3

Advantages - Star Topology

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

4

Disadvantages - Star Topology

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

5

Features - Mesh Topology

Switches/Routers connected so more than one possible route

6

Advantages - Mesh Topology

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

7

Disadvantages - Mesh Topology

Expensive & Difficult - Cables
Redundant Connections

8

Uses - Mesh Topology

Cluster of Surveillance Drones

Military Communications

Smart Devices around the home

9

Features - Ring Topology

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

10

Advantages - Ring Topology

No Data Collisions

11

Disadvantages - Ring Topology

Cable/Device fail - Network fail
Low Performance

12

Features - Bus Topology

One Main cable.
Terminators - stop signals reflecting back

13

Advantages - Bus Topology


Easy to install
Low Cost - Cable

14

Disadvantages - Bus Topology


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

15

Wi-Fi

Wireless connection to Network

Requires a WAP / Router.

Data sent on specific frequency called a channel

16

Advantages - Wi-Fi

Convenient & Low Cost

No Cables - Wander around

Add/Remove Devices easily

Less Disruption to Building/Walls

17

Disadvantages - Wi-Fi

Interference & Signal quality

Less Secure - Hacking

Lower Bandwidth than wired

18

Wi-Fi - Frequency

2.4 Ghz

5 Ghz

19

Features - 2.4 Ghz

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

20

Features - 5 Ghz

Short range
Fast data transmission
(1300 Mbps)

21

Wi-Fi - Channels

Channels 1 - 11

Used for Radio Wave Communication

Interference
Cordless phones, baby monitors.

22

Wi-Fi - Encryption

Data is Scrambled
during communication

Protect from Hackers, unreadable if intercepted.

Recipient needs Key to decode

23

Wi-Fi - Protocols

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

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

24

TCP/IP

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.

25

HTTP

Hyper-Text Transfer Protocol

Allows the browser to communicate with a web server to request and deliver HTML Web Pages

26

HTTPS

Hyper-Text Transfer Protocol Secure

Encrypts connection/data

27

FTP

File Transfer Protocol

Transmit files between client & server

28

POP

Post Office Protocol

Allows Email Clients to retrieve and delete email from an email server

29

IMAP

Internet Message Access Protocol

Allows Email Clients to retrieve email from an email server (not deleted).

30

SMTP

Simple Mail Transfer Protocol

Send emails to Email Server