Unit 5: Networks and Web Technologies

Question 1

What is a network?

Answer 1

A network is two or more computers connected together that can transmit data.

Question 2

What is Physical topology?

Answer 2

Physical topology is the ​physical layout​ of the network.

Question 3

What is Logical topology?

Answer 3

Logical topology is the​ way in which data flows​ around a network.

Question 4

Describe Bus topology.

Answer 4

A network topology where all ​terminals ​(devices) are connected to a backbone cable

Question 5

What is the main advantage of Bus Topology?

Answer 5

Cheaper to set up, doesn’t require any
additional hardware.

Question 6

Name 3 disadvantages of Bus Topology

Answer 6

• If the ​backbone cable fails​, the entire network gets disconnected.
• As traffic increases, ​performance decreases.
• All computers can ​see the data transmission (insecure).

Question 7

Describe Star Topology.

Answer 7

A network topology which uses a central node (​switch/computer​) to direct the flow of data, MAC ​(Media Access Control) addresses identify each device.

Question 8

Name 3 advantages of Star Topology.

Answer 8

• Performance is ​consistent​ even if network is being ​heavily used.
• If one cable fails,​ only that station is affected.
• It’s easy to add new stations.

Question 9

Name 2 disadvantages of Star Topology.

Answer 9

• Expensive​ due to switch and cabling.
• If the central ​switch fails,​ the rest of the network fails.

Question 10

Describe Mesh Topology.

Answer 10

§A network topology where every node is connected to every other node. Most commonly found with wireless technology such as Wi-Fi.

Question 11

Name 3 advantages of Mesh Topology.

Answer 11

• No cabling cost (wireless).
• As nodes increase, the ​reliability and speed​ of network becomes better.
• Fast​er since nodes don’t go through a central switch.

Question 12

Name 2 disadvantages of Mesh Topology.

Answer 12

• You have to purchase devices with wireless capabilities.
• Maintaining the network is ​difficult.

Question 13

What is a protocol?

Answer 13

A protocol is a ​set of rules​ defining how two computers ​communicate​ with each other. Protocols are standard so that all devices have a designated method of communicating with each other, regardless of manufacturer.

Question 14

Name 4 examples of commonly used protocols.

Answer 14

• HTTP (Hypertext Transfer Protocol)​
• TCP/IP​ ​(Transmission Control Protocol / Internet Protocol)
• POP (Post Office Protocol)​ and ​IMAP (Internet Message Access Protocol)​.
• FTP (File Transfer Protocol)​

Question 15

How is the Internet structured?

Answer 15

The Internet is a ​network of networks​ which allows computers on opposite sides of the globe to communicate with each other. Continents are connected to each other using ​large international backbone cables​. Many of these pass ​underwater​, linking continents to one another.

Question 16

What are the 4 operation layers in the TCP/IP Stack?

Answer 16

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

Question 17

Describe the purpose of the Application Layer in the TCP/IP stack.

Answer 17

The application layer specifies ​what protocol​ needs to be used in order to ​relate the application that’s being sent​. For example, if the application is a browser then it would select a protocol such as HTTP, POP3, FTP, etc.

Question 18

Describe the purpose of the Transport Layer in the TCP/IP stack.

Answer 18

The transport layer uses TCP to establish an ​end-to-end connection
between the source and recipient computer.

The transport layer ​splits data up into packets​ and labels these 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.

If any packets get lost, the transport layer ​requests retransmissions of these
lost packets.

Question 19

Describe the purpose of the Network Layer in the TCP/IP stack.

Answer 19

The network layer adds the source and destination ​IP addresses​. (The
combination of the IP address and the port number is called a ​socket
address​.)

Routers​ operate on the network layer and use the IP
addresses to forward the packets.

The sockets are then used to specify which device the packets must be sent
to and the application being used on that device.

Question 20

Describe the purpose of the Link Layer in the TCP/IP stack.

Answer 20

The link layer is the ​connection between the network devices​, it adds the MAC address​ identifying the ​Network Interface Cards​ of the source and destination computers (or router if the device is on another network).

Question 21

Explain the differences between LANs and WANs.

Answer 21

• A LAN is a local area network and a WAN is a wide area network.
• A LAN is a network spread over a ​small geographical area​ while a WAN is typically spread over a ​large geographical area​.
• A WAN usually requires extra ​telecommunication hardware​ owned by third-parties.
• An example of a LAN would be the network in a home, school, or office.
• An example of a WAN is the Internet.