OSI model seven layers in Computer Networks - Mini Project: Build & Apply

Understanding the OSI Model Seven Layers

📖 Scenario: You are learning about how computers communicate over a network. The OSI model helps us understand this communication by dividing it into seven layers, each with a specific role.

🎯 Goal: Build a simple list of the OSI model seven layers in order, then add a brief description for each layer, and finally organize them into a clear structure that shows their sequence and purpose.

📋 What You'll Learn

Create a list called osi_layers with the seven OSI layers in order from top to bottom.

Create a dictionary called layer_descriptions with each layer name as a key and a short description as the value.

Use a for loop with variables layer and description to iterate over layer_descriptions.items().

Create a final list called osi_model that combines each layer name with its description in a formatted string.

💡 Why This Matters

🌍 Real World

Understanding the OSI model helps in troubleshooting network problems and designing network systems.

💼 Career

Network engineers, IT support, and cybersecurity professionals use the OSI model to communicate and solve network issues effectively.

1

Create the OSI layers list

Create a list called osi_layers with these exact seven layers in order: 'Application', 'Presentation', 'Session', 'Transport', 'Network', 'Data Link', 'Physical'.

Computer Networks

# Create the osi_layers list with the seven OSI layers in order
# Your code here

Need a hint?

Remember the OSI model layers start from Application at the top and Physical at the bottom.

2

Add descriptions for each OSI layer

Create a dictionary called layer_descriptions where each key is a layer name from osi_layers and each value is a short description:
'Application': 'User interface and applications',
'Presentation': 'Data translation and encryption',
'Session': 'Managing sessions and connections',
'Transport': 'Reliable data transfer',
'Network': 'Routing and addressing',
'Data Link': 'Data framing and error detection',
'Physical': 'Transmission of raw bits'.

Computer Networks

osi_layers = ['Application', 'Presentation', 'Session', 'Transport', 'Network', 'Data Link', 'Physical']
# Create the layer_descriptions dictionary with exact keys and descriptions
# Your code here

Need a hint?

Use the exact layer names as keys and the given descriptions as values in the dictionary.

3

Iterate over the layer descriptions

Use a for loop with variables layer and description to iterate over layer_descriptions.items(). Inside the loop, create a list called layer_info that stores strings formatted as ': '.

Computer Networks

osi_layers = ['Application', 'Presentation', 'Session', 'Transport', 'Network', 'Data Link', 'Physical']
layer_descriptions = {
    'Application': 'User interface and applications',
    'Presentation': 'Data translation and encryption',
    'Session': 'Managing sessions and connections',
    'Transport': 'Reliable data transfer',
    'Network': 'Routing and addressing',
    'Data Link': 'Data framing and error detection',
    'Physical': 'Transmission of raw bits'
}
layer_info = []
# Use a for loop with layer and description to fill layer_info with formatted strings
# Your code here

Need a hint?

Use an f-string inside the loop to combine the layer name and description.

4

Create the final ordered OSI model list

Create a list called osi_model that contains the formatted strings from layer_info but ordered according to the osi_layers list. Use a list comprehension to match each layer in osi_layers with its description from layer_descriptions in the format ': '.

Computer Networks

osi_layers = ['Application', 'Presentation', 'Session', 'Transport', 'Network', 'Data Link', 'Physical']
layer_descriptions = {
    'Application': 'User interface and applications',
    'Presentation': 'Data translation and encryption',
    'Session': 'Managing sessions and connections',
    'Transport': 'Reliable data transfer',
    'Network': 'Routing and addressing',
    'Data Link': 'Data framing and error detection',
    'Physical': 'Transmission of raw bits'
}
layer_info = []
for layer, description in layer_descriptions.items():
    layer_info.append(f"{layer}: {description}")
# Create osi_model list ordered by osi_layers using a list comprehension
# Your code here

Need a hint?

Use a list comprehension to create the final ordered list matching osi_layers order.