Flow control (stop-and-wait, sliding window) in Computer Networks - Mini Project: Build & Apply

Understanding Flow Control: Stop-and-Wait and Sliding Window

📖 Scenario: You are learning how data is sent over a network between two computers. To avoid losing data or overwhelming the receiver, the sender uses flow control methods.Two common methods are Stop-and-Wait and Sliding Window. You will create simple models to understand how these methods control data flow.

🎯 Goal: Build simple step-by-step models that show how Stop-and-Wait and Sliding Window flow control methods work in sending data packets.

📋 What You'll Learn

Create a list of data packets to send

Set a window size for the sliding window method

Simulate sending packets using Stop-and-Wait method

Simulate sending packets using Sliding Window method

💡 Why This Matters

🌍 Real World

Flow control methods like stop-and-wait and sliding window are used in real networks to ensure data is sent reliably without overwhelming the receiver.

💼 Career

Understanding flow control is important for network engineers and software developers working on communication protocols and network applications.

1

Create the list of data packets

Create a list called packets containing these exact strings: 'Packet1', 'Packet2', 'Packet3', 'Packet4', 'Packet5'.

Computer Networks

# Create the list of packets
# Your code here

Need a hint?

Use square brackets to create a list and put each packet name as a string inside.

2

Set the sliding window size

Create a variable called window_size and set it to the number 3.

Computer Networks

packets = ['Packet1', 'Packet2', 'Packet3', 'Packet4', 'Packet5']
# Set the window size to 3
# Your code here

Need a hint?

Just assign the number 3 to the variable named window_size.

3

Simulate Stop-and-Wait sending

Write a for loop using the variable packet to go through each item in packets. Inside the loop, write a comment # Send packet and wait for acknowledgment to show the stop-and-wait process.

Computer Networks

packets = ['Packet1', 'Packet2', 'Packet3', 'Packet4', 'Packet5']
window_size = 3
# Simulate stop-and-wait sending
# Your code here

Need a hint?

Use a for loop with packet as the variable to go through packets. Inside, add the comment to explain the stop-and-wait step.

4

Simulate Sliding Window sending

Write a for loop using the variable i to go from 0 to len(packets) - window_size + 1. Inside the loop, create a variable window_packets that slices packets from i to i + window_size. Then add a comment # Send packets in the current window.

Computer Networks

packets = ['Packet1', 'Packet2', 'Packet3', 'Packet4', 'Packet5']
window_size = 3
for packet in packets:
    # Send packet and wait for acknowledgment

# Simulate sliding window sending
# Your code here

Need a hint?

Use a for loop with i to slide over the packets list. Slice the list from i to i + window_size to get the current window.