1.3.3: Networks

Question 1

What is a Standard?

Answer 1

• An agreement outlining how companies should manufacture and release certain technologies to that compatibility can be achieved

Question 2

What is a Protocol?

Answer 2

• A rule as to how communication over networks are to be carried out

Question 3

What are some examples of Protocols?

Answer 3

• HyperText Transfer Protocol /Secure [HTTP/S]
• Transmission Control Protocol/Internet Protocol [TCP/IP]
• Internet Message Access Protocol [IMAP]
• Post Office Protocol [POP]
• File Transfer Protocol [FTP]
• Simple Mail Transfer Protocol [SMTP]

Question 4

What is the Internet?

Answer 4

• A network of networks allowing computers to communicate with each other
• Continents are connected to each other using large international backbone cables, many of which pass underwater

Question 5

What is the TCP/IP Stack?

Answer 5

• A stack of networking protocols that work together passing packets during communication

Question 6

What is the order of the layers in the TCP/IP Stack?

Answer 6

• Application Layer
• Transport Layer
• Network Layer
• Link Layer

Question 7

What does the Application Layer in the TCP/IP Stack do?

Answer 7

• Specifies what protocol needs to be used in order to relate the application that’s being sent
• E.g. If the application is a browser then it would select a protocol such as HTTP/S, POP3, or FTP

Question 8

What does the Transport Layer in the TCP/IP Stack do?

Answer 8

• Uses TCP to establish an end-to-end connection between source and recipient computer

Question 9

How does the Transport Layer send data?

Answer 9

• Splits data into packets and labels the packets with their packet number, the total number of packets the original data was split up into, and the port number being used for communication

Question 10

What does the Transmission Layer do if any packets of data get lost?

Answer 10

• The Transport Layer requests retransmissions of the lost packets

Question 11

What does the Network Layer in the TCP/IP Stack do?

Answer 11

• Adds the source and destination IP addresses (The combination of the IP address and port number is the Socket Address)

Question 12

What piece of hardware uses IP addresses?

Answer 12

• Routers that operate on the Network Layer use IP addresses to forward packets

Question 13

What are Socket Addresses used for?

Answer 13

• To specify which device the packets must be sent to and the application being used on that device

Question 14

What does the Link Layer in the TCP/IP Stack do?

Answer 14

• The connection between the network devices, adding MAC addresses identifying the NICs of the source and destination computers
• For devices on the same network, the destination MAC address of the recipient, otherwise the MAC address of the router