653  Layered Models: Review

653.1 Overview

This review consolidates your understanding of network layering models - the foundation for all networking knowledge. The content has been organized into focused chapters for deeper learning.

TipChapter Navigation

This review is split into three focused chapters:

  1. OSI and TCP/IP Comparison - Model fundamentals, key concepts, and chapter summary
  2. Knowledge Checks - 16 MCQs testing layer mapping, addressing, and troubleshooting
  3. Resources and Visual Gallery - Videos, tools, and AI-generated diagrams

653.2 Learning Objectives

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

  • Compare OSI and TCP/IP: Understand the relationship between theoretical and practical models
  • Apply Encapsulation: Trace data flow through network layers with header addition/removal
  • Explain Addressing: Distinguish MAC, IP, and port addressing at different layers
  • Apply ARP: Understand IP-to-MAC resolution for local network communication
  • Evaluate IoT Models: Compare traditional models with IoT-specific reference architectures
  • Identify Standards Bodies: Recognize IEEE, IETF, ISO, and their role in IoT protocols

653.3 Prerequisites

Required Chapters:

Technical Background:

  • OSI model layers
  • TCP/IP model
  • Encapsulation concepts

Estimated Time: 30 minutes (all sections)

653.4 Quick Reference

Layer OSI TCP/IP IoT
7 Application Application MQTT, CoAP
6 Presentation - JSON, CBOR
5 Session - -
4 Transport Transport UDP, TCP
3 Network Internet IPv6, 6LoWPAN
2 Data Link Link 802.15.4, BLE
1 Physical Link Radio

What is this chapter? This review consolidates your understanding of network layering models - the foundation for all networking knowledge.

When to use this chapter:

  • After studying OSI and TCP/IP models
  • Before diving into specific protocols (MQTT, CoAP, etc.)
  • When you need to understand where protocols fit in the stack

Key Models to Know:

Model Layers Use
OSI 7 layers Reference model for understanding
TCP/IP 4 layers Practical internet protocol suite
IoT Stack Varies Application-specific combinations

Why This Matters for IoT: Understanding layers helps you choose the right protocol for each part of your IoT system - from physical connections to application messaging.

Recommended Path:

  1. Start with OSI and TCP/IP Comparison
  2. Test yourself with Knowledge Checks
  3. Explore Resources and Visual Gallery

Deep Dives:

Layer Implementations:

IoT Protocol Mapping:

Comparisons:

Learning:

653.5 Chapter Contents

653.5.1 Part 1: OSI and TCP/IP Comparison

Read the full chapter

Covers:

  • Layer functions as questions (WHAT, HOW reliably, WHERE, HOW to transmit)
  • Key concepts: encapsulation, decapsulation, addressing
  • OSI 7-layer vs TCP/IP 4-layer mapping
  • IoT reference models (Cisco 7-level, ITU-T, IEEE 2413)
  • Common misconception: “More layers = better security”

653.5.2 Part 2: Knowledge Checks

Test your understanding

Covers:

  • Understanding checks: IoT sensor data flow, gateway translation, protocol overhead
  • 16 multiple choice questions with detailed explanations
  • Topics: layer mapping, MAC/IP addressing, ARP, subnet calculations
  • Design challenge: Smart building IP addressing scheme

653.6 Summary

This review solidified understanding of layered network models and their practical application to IoT systems:

  • OSI (7-layer) and TCP/IP (4-layer) models provide theoretical and practical frameworks for organizing network protocols
  • Encapsulation proceeds top-down during transmission with each layer adding headers
  • MAC vs IP addressing: Layer 2 for local delivery, Layer 3 for global routing
  • ARP resolves IP to MAC using broadcast requests and unicast replies
  • IoT reference models extend beyond traditional networking with edge computing, analytics, and business layers

653.7 What’s Next

Continue with the detailed chapters:

  1. OSI and TCP/IP Comparison - Start here for model fundamentals
  2. Knowledge Checks - Test your understanding
  3. Resources and Visual Gallery - Videos and visual references

Or proceed to: