1562  Network Traffic Analysis

1562.1 Overview

Network traffic analysis is the process of capturing, examining, and interpreting data packets flowing through a network. For IoT systems, traffic analysis serves multiple critical purposes: validating protocol implementations, diagnosing connectivity issues, measuring performance, detecting security threats, and understanding device behavior.

This comprehensive topic is covered across four focused chapters:

1562.1.1 Chapter Guide

Chapter Focus Key Topics
Traffic Analysis Fundamentals Capture concepts and strategy Capture points, promiscuous mode, capture vs. display filters
Traffic Capture Tools Tool usage and configuration Wireshark, tcpdump, tshark, specialized IoT sniffers
Analyzing IoT Protocols Protocol-specific analysis MQTT, CoAP, Zigbee, LoRaWAN traffic patterns
Traffic Analysis Testing Testing and monitoring HIL testing, load generation, anomaly detection, worked examples

1562.2 Learning Path

TipRecommended Reading Order

Beginner Path (2-3 hours): 1. Start with Traffic Analysis Fundamentals to understand core concepts 2. Continue to Traffic Capture Tools for hands-on tool usage

Complete Path (4-5 hours): 1. Traffic Analysis Fundamentals - Capture strategy 2. Traffic Capture Tools - Wireshark, tcpdump, tshark 3. Analyzing IoT Protocols - Protocol-specific patterns 4. Traffic Analysis Testing - Production testing and monitoring

1562.3 Key Concepts

Why Traffic Analysis Matters for IoT:

  • Protocol Validation: Verify correct MQTT, CoAP, Zigbee implementations
  • Performance Troubleshooting: Identify latency, packet loss, bandwidth bottlenecks
  • Security Monitoring: Detect unauthorized access, DDoS attacks, compromised devices
  • Debugging Device Behavior: Understand connection failures and erratic behavior
  • Capacity Planning: Measure actual traffic volumes for infrastructure scaling
  • Compliance Verification: Ensure encryption and data transmission requirements

1562.4 Prerequisites

Before diving into traffic analysis, you should be familiar with:

1562.5 Quick Reference

Essential Wireshark Filters:

mqtt                            # All MQTT traffic
coap                            # All CoAP traffic
ip.addr == 192.168.1.100       # Specific device
tcp.analysis.retransmission    # Retransmissions only
frame.time_delta > 1           # Packets with >1s gap

Essential tcpdump Commands:

# Capture MQTT traffic to file
sudo tcpdump -i eth0 port 1883 -w mqtt_capture.pcap

# Remote capture with live Wireshark
ssh user@gateway "tcpdump -w -" | wireshark -k -i -

1562.6 What’s Next

Begin with Traffic Analysis Fundamentals to learn about capture points, promiscuous mode, and filter strategies essential for effective network analysis.