CWNA-108 Certified Wireless Network Administrator Exam

CWNA-108 Objectives

Introduction
The Certified Wireless Network Administrator (CWNA) understands standards and operations of 802.11 wireless networks. Responsibilities include deploying, managing, monitoring, and basic troubleshooting of these networks. The CWNA has the ability to describe devices and operations of current WLAN technologies.

The CWNA exam has no prerequisites; however, the following are recommended before attempting the CWNA exam:
● Basic knowledge of networking (routers, switches, cabling, etc.)
● Basic knowledge of TCP/IP
● At least 1 year of work experience with wireless LAN technologies

The skills and knowledge measured by this examination are derived from a Job Task Analysis (JTA) involving wireless networking experts (CWNEs) and professionals. The results of this JTA were used in weighing the subject areas and ensuring that the weighting is representative of the relative importance of the content.
When you pass the CWNA exam, you earn credit towards the CWSP, CWDP, CWAP, and CWNE certifications and you earn the CWNA certification.
The following chart provides the breakdown of the exam as to the distribution of questions within each knowledge domain.

Radio Frequency (RF) Technologies
WLAN Regulations and Standards
WLAN Protocols and Devices
WLAN Network Architecture and Design Concepts
WLAN Network Security
RF Validation
WLAN Troubleshooting

CWNP Authorized Materials Use Policy
CWNP does not condone the use of unauthorized ‘training materials’ such as ‘brain dumps’. Individuals who utilize such materials to pass CWNP exams will have their certifications revoked. In an effort to more clearly communicate CWNP’s policy on use of unauthorized study materials, CWNP directs all certification candidates to the CWNP Candidate Conduct Policy at:

1.0 Radio Frequency (RF) Technologies – 15%
1.1 Define and explain the basic characteristics of RF and RF behavior
• 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)

1.2 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)

1.3 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

1.4 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

2.0 WLAN Regulations and Standards – 20%
2.1 Explain the roles of WLAN and networking industry organizations
• IEEE
• Wi-Fi Alliance
• IETF
• Regulatory domains and agencies

2.2 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

2.3 Understand spread spectrum technologies, Modulation and Coding Schemes (MCS)
• DSSS
• OFDM
• OFDMA and Resource Units
• BPSK
• QPSK
• QAM (16, 64, 256,1024)

2.4 Identify and apply 802.11 WLAN functional concepts
• Primary channels
• Adjacent overlapping and non-overlapping channels
• Throughput vs. data rate
• Bandwidth
• Guard Interval

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

2.6 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)

2.7 Explain basic use case scenarios for 802.11 wireless networks
• Wireless LAN (WLAN) – BSS and ESS
• Wireless bridging
• Wireless Ad-Hoc (IBSS)
• Wireless Mesh

3.0 WLAN Protocols and Devices – 20%
3.1 Describe the components and functions that make up an 802.11 wireless service set
• Stations (STAs)
• Basic Service Set (BSS) (Infrastructure mode)
• SSID
• BSSID
• Extended Service Set (ESS)
• IBSS (Ad-Hoc)
• Distribution System (DS)
• Distribution System Media (DSM)

3.2 Define terminology related to the 802.11 MAC and PHY
• MSDU, MPDU, PSDU, and PPDU
• A-MSDU and A-MPDU
• PHY preamble and header
3.3 Identify and explain the MAC frame format
• MAC frame format
• MAC addressing
3.4 Identify and explain the purpose of the three main 802.11 frame types
• Management
• Control
• Data

3.5 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

3.6 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

3.7 Explain 802.11 MAC operations
• Roaming
• Power save modes and frame buffering
• Protection mechanisms

3.8 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

4.0 WLAN Network Architecture and Design Concepts– 15%

4.1 Describe and implement Power over Ethernet (PoE) 802.3af, 802.3at, 802.3bt
• 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

4.2 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

4.3 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

4.4 Demonstrate awareness of common proprietary features in wireless networks.
• AirTime Fairness
• Band steering
• Dynamic power and channel management features

4.5 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

5.0 WLAN Network Security – 10%

5.1 Identify weak security options that should not be used in enterprise WLANs
• 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)

5.2 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

5.3 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

5.4 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)

6.0 RF Validation – 10%
6.1 Verify and document that design requirements are met including coverage, throughput, roaming, and connectivity with a post-implementation validation survey
6.2 Locate and identify sources of RF interference
• 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

6.3 Perform application testing to validate WLAN performance
• Network and service availability
• VoIP testing
• Real-time application testing
• Throughput testing

6.4 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

7.0 WLAN Troubleshooting – 10%
7.1 Describe and apply common troubleshooting tools used in WLANs
• 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

7.2 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

QUESTION 1
What can an impedance mismatch in the RF cables and connectors cause?

A. Increased range of the RF signal
B. Fewer MCS values in the MCS table
C. Increased amplitude of the RF signal
D. Excessive VSWR

Correct Answer: D

QUESTION 2
A WLAN transmitter that emits a 50 mW signal is connected to a cable with 3 dB loss. If the cable is connected
to an antenna with 9dBi gain, what is the EIRP at the antenna element?

A. 26 dBm
B. 13 dBm
C. 23 dBm
D. 10 dBm

Correct Answer: C

QUESTION 3
In a long-distance RF link, what statement about Fade Margin is true?

A. A Fade Margin is unnecessary on a long-distance RF link if more than 80% of the first Fresnel zone is clear of obstructions.
B. The Fade Margin is a measurement of signal loss through free space and is a function of frequency and distance.
C. Fade Margin is an additional pad of signal strength designed into the RF system to compensate for unpredictable signal fading.
D. The Fade Margin of a long-distance radio link should be equivalent to the receiver’s low noise filter gain.

Correct Answer: C