Upload
franklin-doyle
View
221
Download
0
Tags:
Embed Size (px)
Citation preview
Unit 1Networks Workbook
What is a computer network?
What is a computer network?
A network is a group of computer and other devices connected together.
Activities
Share files and data
Share printers
Communication (email, social media etc)
Streaming content (videos, TV music)
Storing data (cloud computing)
Accessing the internet
Create a list of the activities computer
networks make possible.
Types of Network
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
Identify the network type from the description.
Bus Topology
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.
Describe the bus topology
Single main cable to which computers are connected.
Ring Topology
Ring topology diagram
Advantages:Better performance than bus topology.
Disadvantages:A failure in any cable or device can take down the entire network.
Describe the bus topology
All computers are connected in a circle.
Star Topology
Star topology diagram
Advantages:A failure in one cable will only take down one computer’s network access.
Disadvantages:Requires more cable.
Describe the bus topology
All computers have their own link to a central computer.
Mesh Topology
Mesh topology diagram
Advantages:Even if one cable fails there is always an alternative.
Disadvantages:High cost and difficult setup.
Describe the bus topology
Where each computer can connect to other computers.
Network Media
Type RangeTransmission 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
Use internet research to complete the table below:
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)
Transmission Time
Scenario Answer (including working)
File Size: 2 KB Speed: 5 Mbps
File Size: 16384 bits
Speed: 5,000,000 bps
Time = 0.0032768
File Size: 3 KB Speed: 1 Mbps
File Size: 24576 bits
Speed: 1,000,000 bps
Time = 0.024576
File Size: 10 KB Speed: 2 Mbps
File Size: 81920 bits
Speed: 2,000,000 bps
Time = 0.04096
Calculate the transmission times for the following scenarios:
Transmission Time
Scenario Answer (including working)
File Size: 1 KB Speed: 10 Mbps
File Size: 8192 bits
Speed: 10,000,000 bps
Time = 0.0008192
File Size: 1 MB Speed: 4 Mbps
File Size: 8388608 bits
Speed: 4,000,000 bps
Time = 2.097152
File Size: 8 KB Speed: 1 Gbps
File Size: 65536 bits
Speed: 1,000,000,000 bps
Time = 0.000065536
Calculate the transmission times for the following scenarios:
Error Detection
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.
Identify the keyword from the description.
Parity Checking
What is parity checking?
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.
Parity Checking
Add an even and an odd parity bit to each of these numbers.
Data being transmitted Even parity Odd parity
1011010 10110100 10110101
0110111 01101111 01101110
1100000 11000000 11000001
0101111 01011110 01011111
Network Addressing
What is a MAC address?
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