WN Podcast 018 – Protocol Analysis Talk with Peter MacKenzie – Part 2

Welcome to our new WiFi Ninjas Podcast episode! This a second part of our protocol analysis discussion with Jedi Grandmaster Peter MacKenzie!

A bit about Peter:

  • CWNE #33
  • Head of Technical Operations at MarQuest Limited
  • Graduated from the University of Hull with a 1st class honours degree
  • Co-author of the CWAP study guide published by Wiley
  • Member of the CWNE Board of Advisers

Do we still call you Peter? We see Jim Palmer is trying to find a new nickname for you 😀

  • Peter Packets?
  • Sir sniff a lot
  • The Duke of Frames
  • Peter McPacketface

A bit about MarQuest limited: – http://www.marquest.com/

  • MarQuest’s customer base includes large organisations across several sectors such as finance, education, government, retail and legal services. Operating from UK offices in Beverley (Yorkshire) and Oxford, we provide services and solutions to all national regions. Our international reputation for technical excellence has led to global provision of services and product supply to countries in mainland Europe, North America and APAC countries (including India and Australia).

Protocol Analysis

  • What is protocol analysis
  • Capturing tools
  • Capture location and duration
  • Capture on a single channel, multiple channel, 1SS, 2SS, etc.
  • Roaming in captures
  • Capture and display filters, colouring, columns, etc.
  • Decryption procedures
  • Other tools: WLAN scanners and discovery tools, captures visualisation and stats
  • Centralised captures and monitoring, alerting and forensic tools
  • Tshoot framework: Define, scale, causes, capture, analyse, observe, remedy, document

Spectrum Analysis

  • What is spectrum analysis
  • Spectrum analysis tools and views
  • Noise and SNR
  • Locate and identify WiFi and non-WiFi interferers based on their RF signature
  • Duty cycle vs spectrum utilisation
  • CCI vs ACI – understand impact of channel interference on WiFi performance
  • Identify 802.11 PHYs looking at FFT

PHY Layers and Technologies

  • PLCP and PMD sublayers
  • PHY technologies in captures: PHY headers, preambles, training fields, frame aggregation and data rates
  • Pseudo-headers: RSSI, rate, MCS, duration, channel, properties, noise, etc.
  • Protocol analysers limits: supported PHYs, SS, SGI, etc.

MAC Sublayer and Functions

  • Frame encapsulation and frame aggregation
  • MAC Frame Format
  • 802.11 Management Frame Formats
  • Data and QoS Data Frame Formats
  • 802.11 Control Frame Formats
  • BSS config: country code, rates, beacons, WMM, RSN, HT/VHT/HE, channels, SSID name, CRC

WLAN Medium Access

  • Distributed Coordination Function (DCF): carrier sense, energy detect, NAV, contention window, random backoff and spacing
  • Enhanced Distributed Channel Access (EDCA)
  • Wi-Fi Multimedia (WMM)
  • Analyse QoS configuration and operations: captures and end-to-end implementation

802.11 Frame Exchanges

  • Discovery, authentication, association
  • EAP and PSK auth
  • 4-way handshake
  • Roaming optimisations (802.11r, v and k) and considerations (sticky clients, excessive roaming)
  • ACK, RTS/CTS, QoS Data, Block ACK
  • Analyse HT/VHT/HE specific transmission methods
  • MIMO, TxBF, MU-MIMO, MRC
  • Frame aggregation (A-MSDU and A-MPDU)
  • Power Saving operations
  • Protection mechanisms
  • Band Steering 

Thanks for listening and enjoy! And comment. And shout if you like it or don’t like it or if you’d like us to talk about anything specific in future episodes!

With tons of love x,

WiFi Ninjas

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