1.3.2 - Wired/Wireless, Protocols & Layers

Question 1

What is an Ethernet?

Answer 1

• A Wired Network
• Used for communicating on a LAN
• A standard for network technologies
• A family of protocols for networking local area networks

Question 2

What are the advantages / disadvantages of the Ethernet?

Answer 2

A:
- Includes protocols & provides reliable, fast communication between two points
D:
- User location is limited by the need for a physical cable connection
- Ethernet relies on lots of cables, connections, ports etc. which affects costs

Question 3

What are Wifi & Bluetooth?

Answer 3

• Wireless networks
  Wifi:
• Wifi has a larger range than bluetooth (100m > 10m)
• A suite of protocols allowing devices to connect to a wireless network
  Bluetooth:
• A method of exchanging data wirelessly over short distances, (much shorter than Wi-Fi)
• Protocol for the transmission of data using short-wavelength UHF radio waves

Question 4

What are the advantages of WiFi?

Answer 4

• Users can move around freely
• Easier & less expensive to set up
• Convenient
• Can handle large number of users
• Transferring info is much easier

Question 5

What are the disadvantages of WiFi?

Answer 5

• Slower speed than wired networks
• Relies on signal strength
• Signal can be obstructed
• Less secure

Question 6

What are the advantages / disadvantages of Bluetooth?

Answer 6

• Ideal for connecting personal devices
• Short range (10m)
• Low power consumption compared to WiFi

Question 7

What is a Wired Connection?

Answer 7

Media for physically connecting network end points

Question 8

What is a Wireless Connection?

Answer 8

Any connection made between two or more devices which does not involve the need for a physical connection

Question 9

What is Encryption?

Answer 9

Encoding readable data called plaintext into unreadable data called ciphertext using a key

Question 10

Why is Encryption important?

Answer 10

• Wireless Networks broadcast data, so it needs to be encrypted to be secure

Question 11

How does Encryption work?

Answer 11

• Data is scrambles into cipher text using a master key created from the SSID and password
• Decrypted by receiver using the same master key, so key is not transmitted

Question 12

What is an IP Address?

Answer 12

Used to route packets on a WAN
A unique string of numbers separated by full stops that identify each computer using the Internet Protocol to communicate over a network

Question 13

What are the formats of an IP Address?

Answer 13

IPv4:
- 32 bits, 4 numbers in range 0-255
eg. 128.69.1.0

IPv6:
- 128 bits, eight groups of hex values
eg. 2001:0db8:85a3:0000:0000:9a2e:0370:7334

Question 14

What is a MAC Address?

Answer 14

• Assigned to devices & used to route frames on a LAN
• Unique to every network interface card
• A unique identifier assigned to a network interface card for communications at the data link layer of a local network

Question 15

What are Standards?

Answer 15

A set of specifications for hardware & software

Question 16

Why are standards useful?

Answer 16

• It allows manufacturers & producers to create products and services that are compatible
• Most devices wouldn’t be able to successfully communicate/interact without standards

Question 17

What is a Protocol?

Answer 17

A set of rules that allows two devices to communicate

Question 18

TCP/IP

Answer 18

Transmission Control Protocol/Internet Protocol
- TCP Provides error free transmission between two routers
- IP Routes packets across a WAN
- Both make the TCP/IP protocol stack

Question 19

HTTP

Answer 19

Hyper Text Transfer Protocol
- A client-server method of requesting & delivering HTML web pages

Question 20

HTTPS

Answer 20

Hyper Text Transfer Protocol Secure
- Encryption and authentication for requesting & delivering HTML web pages
- Used when secure info needs to be transferred, like bank details

Question 21

FTP

Answer 21

File Transfer Protocol
- Sends files between computers, usually on a WAN

Question 22

POP

Answer 22

Post Office Protocol
- Retrieves emails from a mail server, removes it & transfers to your device

Question 23

SMTP

Answer 23

Simple Mail Transfer Protocol
- Sends emails to an email server

Question 24

IMAP

Answer 24

Internet Message Access Protocol
- Used by mail clients to manage remote mail boxes & retrieve emails from a mail server

Question 25

What is Layering?

Answer 25

Divide a complex task of networking into smaller, simpler tasks that work with each other

Question 26

What are the advantages of Layering?

Answer 26

- Reduces complexity of the problem into manageable sub-programs - Devices can be manufactured to operate at a particular layer - Products from different vendors will work together

Question 27

How layers are used in protocols

Answer 27

Layer 4 : Browser using HTTPS 3 : TCP Error Handling 2 : IP Routing 1 : MAC Frames sent over