WebSockets for real-time communication in Computer Networks - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

How WebSockets differ from HTTP in real-time communication

Which statement best explains how WebSockets differ from traditional HTTP for real-time communication?

A WebSockets only allow the server to send data, while HTTP allows both client and server to send data.

B WebSockets establish a persistent connection allowing two-way communication, while HTTP opens a new connection for each request-response cycle.

C WebSockets use the UDP protocol, whereas HTTP uses TCP, making WebSockets faster for real-time data.

D WebSockets require a new handshake for every message sent, unlike HTTP which maintains a single handshake.

💡 Hint

Think about how connections are maintained during communication.

WebSockets create a single, persistent connection that stays open, enabling both client and server to send messages anytime. HTTP opens and closes connections for each request and response.

📋 Factual

intermediate

WebSocket handshake process

What is the purpose of the WebSocket handshake in establishing a connection?

A To encrypt the data transmitted over the WebSocket connection.

B To authenticate the client using username and password before opening the connection.

C To upgrade an existing HTTP connection to a WebSocket connection by agreeing on protocol details.

D To close the connection after data transfer is complete.

💡 Hint

Consider how WebSockets start from an HTTP connection.

The handshake upgrades a normal HTTP connection to a WebSocket connection by exchanging headers that confirm both sides support WebSockets.

🚀 Application

advanced

Choosing WebSockets for a chat application

You are building a chat app that requires instant message delivery between users. Why is using WebSockets a better choice than HTTP polling?

A WebSockets reduce latency by maintaining an open connection, allowing instant message delivery without repeated requests.

B WebSockets guarantee message delivery order, while HTTP polling does not.

C WebSockets use less bandwidth because they compress messages by default, unlike HTTP polling.

D WebSockets automatically store messages on the server for offline users, unlike HTTP polling.

💡 Hint

Think about how often data is sent and how connections are managed.

WebSockets keep a connection open so messages can be sent instantly without the delay of repeated HTTP requests, reducing latency significantly.

🔍 Analysis

advanced

Impact of network interruptions on WebSocket connections

What happens to an active WebSocket connection if the network temporarily disconnects and then reconnects?

A The WebSocket connection closes and must be re-established by the client after reconnection.

B The WebSocket automatically resumes without any action needed from client or server.

C The server buffers all messages during disconnection and sends them once the client reconnects.

D The connection switches to HTTP polling mode until the network stabilizes.

💡 Hint

Consider how persistent connections behave when interrupted.

WebSocket connections do not automatically resume after network loss; the connection closes and the client must reconnect to continue communication.

❓ Reasoning

expert

Security considerations with WebSockets

Which of the following is the most important security measure when using WebSockets in a public web application?

A Disable all cookies to prevent session hijacking over WebSockets.

B Use HTTP instead of WebSockets to avoid security risks.

C Only allow WebSocket connections from localhost to avoid external attacks.

D Use Secure WebSockets (wss://) to encrypt data and prevent eavesdropping.

💡 Hint

Think about how data travels over the network and how to protect it.

Using Secure WebSockets (wss://) encrypts the data sent over the connection, protecting it from interception and tampering.