WebSockets for real-time communication in Computer Networks - Mini Project: Build & Apply

WebSockets for Real-Time Communication

📖 Scenario: You are building a simple chat application that allows users to send messages instantly without refreshing the page. To do this, you will learn how WebSockets enable real-time communication between a client and a server.

🎯 Goal: Build a basic understanding of WebSockets by creating a step-by-step outline of how a WebSocket connection is established, configured, used to send and receive messages, and properly closed.

📋 What You'll Learn

Define the initial WebSocket URL to connect to the server

Set up a configuration variable for connection protocols

Write the core logic to open the WebSocket and send a message

Add the final step to close the WebSocket connection properly

💡 Why This Matters

🌍 Real World

WebSockets are used in chat apps, live notifications, online games, and any app needing instant updates without refreshing the page.

💼 Career

Understanding WebSockets is important for web developers, network engineers, and software engineers working on real-time applications.

1

DATA SETUP: Define the WebSocket URL

Create a variable called websocket_url and set it to the string "wss://example.com/chat" which represents the WebSocket server URL.

Computer Networks

# Create the WebSocket URL variable
# Your code here

Need a hint?

The WebSocket URL usually starts with wss:// for secure connections.

2

CONFIGURATION: Set WebSocket protocols

Create a variable called protocols and set it to a list containing the string "chat" to specify the subprotocol for the WebSocket connection.

Computer Networks

websocket_url = "wss://example.com/chat"
# Define the protocols list
# Your code here

Need a hint?

Protocols help the server and client agree on the type of communication.

3

CORE LOGIC: Open WebSocket and send a message

Create a variable called ws that opens a WebSocket connection using websocket_url and protocols. Then write a line to send the message "Hello, WebSocket!" through ws.

Computer Networks

websocket_url = "wss://example.com/chat"
protocols = ["chat"]
# Open the WebSocket connection and send a message
# Your code here

Need a hint?

Use the WebSocket constructor with URL and protocols, then call send() to send a message.

4

COMPLETION: Close the WebSocket connection

Write a line to close the WebSocket connection by calling the close() method on the ws variable.

Computer Networks

websocket_url = "wss://example.com/chat"
protocols = ["chat"]
ws = WebSocket(websocket_url, protocols=protocols)
ws.send("Hello, WebSocket!")
# Close the WebSocket connection
# Your code here

Need a hint?

Always close the WebSocket connection when done to free resources.