663 IoT Protocols: Fundamentals

Learning Objectives

By the end of this section, you will be able to:

Understand why traditional internet protocols need adaptation for IoT
Identify protocols at each layer of the IoT protocol stack
Compare IPv4 and IPv6 for IoT applications
Understand the role of 6LoWPAN in IoT networks
Compare CoAP and MQTT application protocols
Map protocols to the TCP/IP layer model
Select appropriate protocols for different IoT scenarios

663.1 Chapter Overview

This chapter provides a comprehensive guide to IoT protocol fundamentals. The content has been organized into three focused chapters for easier learning:

663.1.1 Chapter Guide

Chapter	Topic	Key Content	Time
1	IoT Protocols: Introduction	Why IoT needs specialized protocols, device constraints, beginner content	15 min
2	IoT Protocols: Stack Architecture	Complete protocol stack, layer-by-layer breakdown, protocol categories, understanding checks	25 min
3	IoT Protocols: Scenarios and Interview Prep	System design, MQTT QoS, 6LoWPAN compression, troubleshooting, technical interviews	30 min

663.1.2 Quick Reference: Protocol Stack

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flowchart TD
    subgraph Application["Application Layer"]
        A1[CoAP]
        A2[MQTT]
        A3[HTTP]
    end

    subgraph Transport["Transport Layer"]
        T1[UDP]
        T2[TCP]
    end

    subgraph Network["Network Layer"]
        N1[IPv6]
        N2[6LoWPAN]
    end

    subgraph Link["Data Link Layer"]
        L1[802.15.4]
        L2[BLE]
        L3[LoRaWAN]
    end

    Application --> Transport
    Transport --> Network
    Network --> Link

    style Application fill:#E67E22,stroke:#2C3E50,color:#fff
    style Transport fill:#16A085,stroke:#2C3E50,color:#fff
    style Network fill:#2C3E50,stroke:#16A085,color:#fff
    style Link fill:#7F8C8D,stroke:#2C3E50,color:#fff

Figure 663.1

663.1.3 Key Concepts at a Glance

Concept	What It Does	Why It Matters
6LoWPAN	Compresses IPv6 headers from 40 to 2-7 bytes	Enables IPv6 on constrained 802.15.4 networks
CoAP	RESTful protocol over UDP with 4-byte header	10x more efficient than HTTP for IoT
MQTT	Publish-subscribe messaging over TCP	Scales to millions of devices via broker
IPv6	340 undecillion addresses	Every IoT device gets unique global address

663.1.4 Learning Path Recommendations

For Beginners: Start with IoT Protocols: Introduction to understand why specialized protocols matter, including beginner-friendly explanations and the Sensor Squad section for kids.

For Practitioners: Jump to IoT Protocols: Stack Architecture for protocol selection decision trees and understanding checks with real-world scenarios.

For Interview Prep: Work through IoT Protocols: Scenarios and Interview Prep for technical deep-dives on MQTT QoS, 6LoWPAN compression, and system design questions.

663.2 Videos

Protocol Stack Overview

Lesson 4 — foundational networking concepts used across IoT protocols.

Application Protocols in Context

Lesson 4 — MQTT vs CoAP vs HTTP vs AMQP and when to use each.

663.3 What’s Next?

Start your journey through IoT protocols with IoT Protocols: Introduction to understand why traditional internet protocols need adaptation for resource-constrained devices.

Related Chapters

Deep Dives: - IoT Protocols Labs and Selection - Hands-on protocol implementation and selection frameworks - IoT Protocols Review - Comprehensive protocol comparison and assessment

Application Protocols: - MQTT Fundamentals - Lightweight pub/sub messaging for IoT - CoAP Fundamentals and Architecture - RESTful protocol for constrained devices - Application Protocols - HTTP, MQTT, CoAP, AMQP comparison

Network Layer: - 6LoWPAN Fundamentals and Architecture - IPv6 header compression for 802.15.4 - IPv6 for IoT - IPv6 addressing and deployment

Link Layer Technologies: - 802.15.4 Fundamentals - Low-power wireless MAC and PHY - Wi-Fi Fundamentals and Standards - Wi-Fi for IoT applications - Bluetooth Fundamentals - BLE for personal area networks

Foundational Concepts: - Layered Models Fundamentals - OSI and TCP/IP model foundations - Networking Basics - Core networking principles

Learning: - Simulations Hub - Interactive protocol demonstrations - Videos Hub - Protocol stack video tutorials