1. Networks Workbook

2. What is a computer network?
A network is a group of computer and other devices connected together.
Create a list of the activities computer networks make possible.
Activities
Share files and data
Share printers
Communication ( , social media etc)
Streaming content (videos, TV music)
Storing data (cloud computing)
Accessing the internet

3. Identify the network type from the description.
Types of Network
Identify the network type from the description.
Type of Network
Description
Example
Wide Area Network (WAN)
Connect computers over a large area such as a town, city or country.
The internet (a global computer network)
Local Area Network (LAN)
Connect computers over a building or a site.
School network
Personal Area Network (PAN)
Connect computers or devices used by one person.
Bluetooth headset connected to a mobile phone

4. Bus Topology Advantages:
Describe the bus topology
Single main cable to which computers are connected.
Bus topology diagram
Advantages:
Easy to install and doesn’t require much cabling.
Disadvantages:
If the main cable fails the entire network will go down.

5. Ring Topology Advantages: Better performance than bus topology.
Describe the bus topology
All computers are connected in a circle.
Ring topology diagram
Advantages:
Better performance than bus topology.
Disadvantages:
A failure in any cable or device can take down the entire network.

6. Star Topology Advantages:
Describe the bus topology
All computers have their own link to a central computer.
Star topology diagram
Advantages:
A failure in one cable will only take down one computer’s network access.
Disadvantages:
Requires more cable.

7. Mesh Topology Advantages:
Describe the bus topology
Where each computer can connect to other computers.
Mesh topology diagram
Advantages:
Even if one cable fails there is always an alternative.
Disadvantages:
High cost and difficult setup.

8. Use internet research to complete the table below:
Network Media
Use internet research to complete the table below:
Type
Range
Transmission Speed
Security (Good, Medium, Poor)
Copper Cable
Up to 500m
1000 Mbps
Medium
Fibre Optic Cable
Up to 10,000m
100 Gbps
Good
Wireless
Up to 250m
600 Mbps
Poor

9. Transmission Speed Data transmission speeds are measured in:
Bits per second (bps).
Data storage is measured in:
Bits per second (bps).
The formula used to calculate how long it will take to transfer a file:
Time = size of file (bits) / network speed (bits)

10. Calculate the transmission times for the following scenarios:
Answer (including working)
File Size: 2 KB Speed: 5 Mbps
File Size: bits
Speed: 5,000,000 bps
Time =
File Size: 3 KB Speed: 1 Mbps
File Size: bits
Speed: 1,000,000 bps
Time =
File Size: 10 KB Speed: 2 Mbps
File Size: bits
Speed: 2,000,000 bps
Time =

11. Calculate the transmission times for the following scenarios:
Answer (including working)
File Size: 1 KB Speed: 10 Mbps
File Size: 8192 bits
Speed: 10,000,000 bps
Time =
File Size: 1 MB Speed: 4 Mbps
File Size: bits
Speed: 4,000,000 bps
Time =
File Size: 8 KB Speed: 1 Gbps
File Size: bits
Speed: 1,000,000,000 bps
Time =

12. Identify the keyword from the description.
Error Detection
Identify the keyword from the description.
Keyword
Description
Checksum
A checksum is an algorithm used to check for errors in data transmission. It works by calculating a numerical value based on the number of bits in a packed of data. This value is attached to the packet.
When the packet reaches its destination, the same checksum algorithm is applied to the data. If the two checksums don’t match it shows that an error has occurred and the receiving computer asks the sending computer to re-send that package.

13. Parity Checking What is parity checking? What is even parity?
Parity checking is a simple form of error detection. A parity bit is added to the end of a string of binary code to indicate whether the number of bits in the string with the value 1 is even or odd. There are two type of parity bits:
What is even parity?
Where the bit is set to 1 if the number of bits is odd. The extra parity bit will make the number of 1s even.
What is odd parity
Where the parity bit is set to 1 if the number of bits is even. The extra parity bit will make the number of 1s odd.

14. Parity Checking
Add an even and an odd parity bit to each of these numbers.
Data being transmitted
Even parity
Odd parity

15. Network Addressing What is a MAC address? What is a hostname?
A MAC address is a unique number written into the network card, composed of six pairs of hexadecimal characters.
What is a hostname?
A host name is a human-readable label that is assigned to a network device.
Give an example of a MAC address
00:10:5A:44:12:B5