1.3.2 Wired And Wireless Networks, Protocols And Layers

Question 1

IP Addressing

Answer 1

(v4) Example : 192.192.72.1
- Dotted decimal, 4 numbers each in range 0 - 255

(v6) Example : abcd:1234:ab34:12cd:a23d:0000:1234:cdef
- Separator is a colon, 16 pairs (8 quadruples) of hexadecimal digits in range of 0000 - ffff

• Uniquely identifies a computer on the INTERNET
• Logical addresses
• Used by routers on the Internet to make routing decisions on where to send/route packets
• A router has a table that lists the IP addresses of all networks that are connected to it and its physical ports, and will look up the IP address of a PACKET in that table to decide which port to send the packet out from

Question 2

MAC Addressing

Answer 2

Example : ab:a1:f2:c5:77:ef
- Separator is a colon, 6 pairs of hexadecimal digits in range of 00 - ff

• Uniquely identifies a computer on the LAN
• Stored (permanently) on the NIC
• A switch has a table that lists the MAC address of all computers connected to it and its physical ports, and will look up the MAC address of a FRAME in that table to decide which port to send the frame out form

Question 3

Encryption

Answer 3

Used when data is jumbled up so that it cannot be understood (NOT READ!!!)

Question 4

Protocols

Answer 4

A network protocol is an agreed set of rules that devices follow in order to communicate with each other

Question 5

TCP/IP (Transmission Control Protocol/Internet Protocol)

Answer 5

TCP - covers the parts of transmitting data :
- The encapsulation of data into packets
- Error detection and correction
- Flow control

IP - covers communication on the Internet

Question 6

HTTP (Hyper Text Transfer Protocol)

Answer 6

Covers the transfer of web pages (HTML documents) from web servers to clients

Question 7

HTTPS (Hyper Text Transfer Protocol Secure)

Answer 7

Covers the encrypted transfer of web pages from web servers to clients

Question 8

FTP (File Transfer Protocol)

Answer 8

Used to transfer files from a files server to a client (or vice versa)

Question 9

POP (Post Office Protocol)

Answer 9

Used for downloading an email from a mail server and REMOVES it from the server in the process

Question 10

IMAP (Internet Message Access Protocol)

Answer 10

Used for downloading an email from a mail server BUT leaves a COPY of it on the server

Question 11

SMTP (Simple Mail Transfer Protocol)

Answer 11

Used for sending an email (and transferring from one mail server to another)

Question 12

Ethernet

Answer 12

• A protocol that describes how communication should occur in a LAN
• Covers the PHYSICAL media, the use of MAC address in deciding where a DATA FRAME should be sent
• Covers what should happen in the event of collision

Question 13

WiFi

Answer 13

• A COLLECTION of protocol that describes how communication should occur WIRELESSLY
• Covers the FREQUENCIES and CHANNELS used using radio waves
• Covers authentication to the wireless network

Question 14

Bluetooth

Answer 14

• A WIRELESS protocol that describes SHORT RANGE communication using ULTRA-HIGH FREQUENCY RADIO WAVES
• Typically used for sharing files and connecting devices such as headphones

Question 15

Layers

Answer 15

Protocols can be grouped together in layers based upon their role

Aids with development of new protocols, as it allows development, only focusing upon its interactions with other elements of that layer and how it interfaces with adjacent layers

Question 16

Standards

Answer 16

A networking standard is an agreed and documented way for networks to communicate

Typically a collection of protocols