Chapter 2. Communication

Question 1

What is a network topology

Answer 1

An arrangement of devices in a network

Question 2

What is a network

Answer 2

A link between two or more computers through which they communicate, enabling them to share data, software and hardware.

Question 3

Advantages of a network

Answer 3

• Enables files and data to be backed up centrally
• Allows sharing copies of software(multiuser licenses are cheaper)
• Allow multi-access to files
• Hardware resources such as printers and internet connections can be shared
• Communicate with network users (instant messaging, email, video conferencing
• Licences are cheaper when used on a network than on standalone machines

Question 4

Disadvantages of networks

Answer 4

• More difficult to secure as compared to standalone systems and they are vulnerable to hacking, phishing and pharming
• If server breaks down, work comes to a standstill
• Viruses spread more easily in network environments
• Managing large networks can be a complex task
• There’s an expensive initial investment in infrastructure(servers and cabling)

Question 5

Expand the acronym APRAnet

Answer 5

Advanced Research Projects Agency Network

Question 6

What are the advantages of a bus network

Answer 6

1. Continues to function even when one node fails
2. Easy to expand - just adding more nodes

Question 7

What are the disdvantages of a bus network

Answer 7

1. Fails if the main cable fails
2. Performance detiriorates under heavy load
3. Not secure since each packect passes through every node

Question 8

Differentiate between a hub and a switch

Answer 8

A hub sends packets to all devices in a star configuration but only the node with the matching address accepts the packet whilst a swith only sends the packets to the node with the right address

Question 9

Advantages of a star topology

Answer 9

1. Data collisions are greatly reduced
2. More secure since security methods can be applied to the central node
3. Easy to improve just by installing an upgraded hub
4. If one connection is broken then only one node is affected

Question 10

Disadvantages of star topologies

Answer 10

1. Initial installation costs are high
2. If the hub/switch fails, the whole network goes down

Question 11

Give the names and explain the two types of data transfer incorporated by mesh networks

Answer 11

1. Routing
   The nodes are given routing logic and data is directed to its destination by the shortest route possible
2. Flooding
   Data is just send via every node to its destination

Question 12

What are the advantages of mesh networks

Answer 12

• Easy to identify where faults occured
• Broken links do not affect the whole network
• Good privacy and security
• Relatively easy to expand

Question 13

What are the disadvantages of mesh networks

Answer 13

• A large amount of cabling is required
• Set-up and maintenance is difficult and complex