Free course

Socket Programming with Node.js

Build TCP and UDP programs with Node.js, frame messages, handle unreliable connections, and design a small protocol you can inspect on the wire.

5 modules · 25 lessons · No signup

Prerequisites: JavaScript, Node.js and Networking Foundations

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What you'll learn

Build and test TCP and UDP clients and servers that frame input, apply limits, handle failures, and support multiple clients safely.

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Course contents

  1. TCP foundations

    Build a TCP server and client, exchange bytes, and control the listening address.

    1. ✓ Build a TCP server
    2. ✓ Build a TCP client
    3. ✓ Treat TCP as a byte stream
    4. ✓ Choose a listening address
    5. ✓ Check your understanding: tcp foundations

  2. Message framing

    Build a newline protocol, buffer partial input, parse JSON messages, and enforce size limits.

    1. ✓ Design a newline protocol
    2. ✓ Buffer partial lines
    3. ✓ Send length-prefixed messages
    4. ✓ Frame JSON messages
    5. ✓ Check your understanding: message framing

  3. Connection reliability

    Handle timeouts, half-closes, resets, backpressure, and cleanup without leaking resources.

    1. ✓ Add an idle timeout
    2. ✓ Handle end, close, and errors
    3. ✓ Respect backpressure
    4. ✓ Limit connections and work
    5. ✓ Check your understanding: connection reliability

  4. UDP datagrams

    Build UDP endpoints, preserve message boundaries, and add retries, identifiers, and duplicate handling.

    1. ✓ Build a UDP server
    2. ✓ Send a UDP datagram
    3. ✓ Add request identifiers
    4. ✓ Design for loss and reordering
    5. ✓ Check your understanding: udp datagrams

  5. Build and test a protocol

    Specify commands, validate limits, support concurrent clients, inspect packets, and finish a small service.

    1. ✓ Write the protocol contract
    2. ✓ Validate before changing state
    3. ✓ Support concurrent clients
    4. ✓ Capture and finish the service
    5. ✓ Check your understanding: build and test a protocol