Study with CWNA-108 most valid questions & verified answers

• Use of protocol analyzers for troubleshooting tasks
• Use of spectrum analyzers for identifying sources of interference
• Use of management, monitoring and logging systems for troubleshooting tasks
• Use of wireless LAN scanners for troubleshooting tasks

2. Identify and troubleshoot common wireless issues

• Identify causes of insufficient throughput in the wireless distribution systems including LAN port speed/duplex misconfigurations, insufficient PoE budget, and insufficient Internet or WAN bandwidth
• Identify and solve RF interference using spectrum analyzers
• Identify wireless performance issues using SNR, retransmissions, and airtime utilization statistics
• Identify causes of wireless issues related to network services including DHCP, DNS, and time protocols including using native interface and IP configuration tools (e.g. pings, DNS lookups, interface configuration)
• Identify wireless issues related to security configuration mismatches

• Wavelength, frequency, amplitude, phase, sine waves
• RF propagation and coverage
• Reflection, refraction, diffraction and scattering
• Multipath and RF interference
• Gain and loss
• Amplification
• Attenuation
• Absorption
• Voltage Standing Wave Ratio (VSWR)
• Return Loss
• Free Space Path Loss (FSPL)

2. Apply the basic concepts of RF mathematics and measurement

• Watt and milliwatt
• Decibel (dB)
• dBm and dBi
• Noise floor
• SNR
• RSSI
• dBm to mW conversion rules of 10 and 3
• Equivalent Isotropically Radiated Power (EIRP)

3. Identify RF signal characteristics as they relate to antennas.

• RF and physical line of sight and Fresnel zone clearance
• Beamwidths
• Passive gain
• Polarization
• Antenna diversity types
• Radio chains
• Spatial multiplexing (SM)
• Transmit Beamforming (TxBF)
• Maximal Ratio Combining (MRC)
• MIMO

4. Explain and apply the functionality of RF antennas, antenna systems, and accessories available

• Omni-directional antennas
• Semi-directional antennas
• Highly directional antennas
• Reading Azimuth and Elevation charts for different antenna types
• Antenna orientation
• RF cables and connectors
• Lightning arrestors and grounding rods/wires

• Stations (STAs)
• Basic Service Set (BSS) (Infrastructure mode)
• SSID
• BSSID
• Extended Service Set (ESS)
• IBSS (Ad-Hoc)
• Distribution System (DS)
• Distribution System Media (DSM)

2. Define terminology related to the 802.11 MAC and PHY

• MSDU, MPDU, PSDU, and PPDU
• A-MSDU and A-MPDU
• PHY preamble and header

3. Identify and explain the MAC frame format

• MAC frame format
• MAC addressing

4. Identify and explain the purpose of the three main 802.11 frame types

• Management
• Control
• Data

5. Explain the process used to locate and connect to a WLAN

• Scanning (active and passive)
• Authentication
• Association
• Open System Authentication and Shared Key authentication
• Connecting to 802.1X/EAP and Pre-Shared Key authentication networks
• BSS selection
• Connecting to hidden SSIDs

6. Explain 802.11 channel access methods

• DCF
• EDCA
• RTS/CTS
• CTS-to-Self
• NAV
• Interframe spaces (SIFS, DIFS, EIFS, AIFS)
• Physical carrier sense and virtual carrier sense
• Hidden node

7. Explain 802.11 MAC operations

• Roaming
• Power save modes and frame buffering
• Protection mechanisms

8. Describe features of, select, and install WLAN devices, control, and management systems

• Access Points (APs)
• WLAN controllers
• Wireless network management systems
• Wireless bridge and mesh APs
• Client devices

• WEP
• Shared Key authentication
• SSID hiding as a security mechanism
• MAC filtering
• Use of deprecated security methods (e.g. WPA and/or WPA2 with TKIP)
• Wi-Fi Protected Setup (WPS)

2. Identify and configure effective security mechanisms for enterprise WLANs

• Application of AES with CCMP for encryption and integrity
• WPA2-Personal including limitations and best practices for pre-shared (PSK) use
• WPA2-Enterprise -configuring wireless networks to use 802.1X including connecting to RADIUS servers and appropriate EAP methods

3. Understand basic concepts of WPA3 and Opportunistic Wireless Encryption (OWE) and enhancements compared to WPA2

• Understand basic security enhancements in WPA3 vs. WPA2
• Understand basic security enhancements of encryption and integrity in WPA3 (e.g. CCMP, GCMP, AES)
• Simultaneous Authentication of Equals (SAE) in WPA3 as an enhancement for legacy pre-shared key technology
• Understand the purpose of Opportunistic Wireless Encryption (OWE) for public and guest networks

4. Describe common security options and tools used in wireless networks

• Access control solutions (e.g. captive portals, NAC, BYOD)
• Protected management frames
• Fast Secure Roaming methods
• Wireless Intrusion Prevention System (WIPS) and/or rogue AP detection
• Protocol and spectrum analyzers
• Best practices in secure management protocols (e.g. encrypted management HTTPS, SNMPv3, SSH2, VPN and password management)

• Power Source Equipment
• Powered Device
• Midspan and endpoint PSEs
• Power classes to include power differences between PSE and PD
• Power budgets and powered port density

2. Define and describe differences, advantages and constraints of the different wireless LAN architectures

• Centralized data forwarding
• Distributed data forwarding
• Control, Management and Data planes
• Scalability and availability solutions
• Tunneling, QoS and VLANs

3. Describe design considerations for common deployment scenarios in wireless such as coverage requirements, roaming considerations, throughput, capacity and security

• Design considerations for data
• Design considerations for voice
• Design considerations for video
• Design considerations for location services including Real-Time Location Services (RTLS)
• Design considerations for highly mobile devices (e.g. tablets and smartphones)
• Capacity planning for high and very high-density environments
• Design considerations for guest access/BYOD
• Design considerations for supporting legacy 802.11 devices

4.Demonstrate awareness of common proprietary features in wireless networks.

• AirTime Fairness
• Band steering
• Dynamic power and channel management features

5. Determine and configure required network services supporting the wireless network

• DHCP for client addressing, AP addressing and/or controller discovery
• DNS for address resolution for clients and APs
• Time synchronization protocols (e.g. NTP, SNTP)
• VLANs for segmentation
• Authentication services (e.g. RADIUS, LDAP)
• Access Control Lists for segmentation
• Wired network capacity requirements

• IEEE
• Wi-Fi Alliance
• IETF
• Regulatory domains and agencies

2. Explain and apply the various Physical Layer (PHY) solutions of the IEEE 802.11-2016 standard as amended including supported channel widths, spatial streams, data rates.

• DSSS – 802.11
• HR-DSSS – 802.11b
• OFDM – 802.11a
• ERP – 802.11g
• Wi-Fi 4 - HT – 802.11n
• Wi-Fi 5 - VHT – 802.11ac
• Wi-Fi 6 - HE - 802.11ax

3. Understand spread spectrum technologies, Modulation and Coding Schemes (MCS)

• DSSS
• OFDM
• OFDMA and Resource Units
• BPSK
• QPSK
• QAM (16, 64, 256,1024)

4. Identify and apply 802.11 WLAN functional concepts

• Primary channels
• Adjacent overlapping and non-overlapping channels
• Throughput vs. data rate
• Bandwidth
• Guard Interval

5. Describe the OSI model layers affected by the 802.11-2016 standard and amendments

6. Identify and comply with regulatory domain requirements and constraints (specifically in 2.4 GHz and 5 GHz)

• Frequency bands used by the 802.11 PHYs
• Available channels
• Regulatory power constraints
• Dynamic Frequency Selection (DFS)
• Transmit Power Control (TPC)

7. Explain basic use case scenarios for 802.11 wireless networks

• Wireless LAN (WLAN) – BSS and ESS
• Wireless bridging
• Wireless Ad-Hoc (IBSS)
• Wireless Mesh

• Identify RF disruption from 802.11 wireless devices including contention vs. interference and causes/sources of both including co-channel contention (CCC), overlapping channels, and 802.11 wireless device proximity
• Identify sources of RF interference from non-802.11 wireless devices based on the investigation of airtime and frequency utilization
• Understand interference mitigation options including removal of interference source or change of wireless channel usage

3. Perform application testing to validate WLAN performance

• Network and service availability
• VoIP testing
• Real-time application testing
• Throughput testing

4. Understand and use the basic features of validation tools

• Use of throughput testers for validation tasks
• Use of wireless validation software (specifically survey software and wireless scanners)
• Use of protocol analyzers for validation tasks
• Use of spectrum analyzers for validation tasks