CWS CWS Network Performance & Optimization 1 — Questions and Answers
Question 1: What is the primary cause of the 'sticky client' problem in WLANs?
- Clients connecting to hidden SSIDs
- Clients holding onto a weak AP association instead of roaming to a stronger AP (Correct answer)
- Duplicate IP address conflicts
- DNS resolution failures
Correct answer: Clients holding onto a weak AP association instead of roaming to a stronger AP
Sticky clients are devices that remain associated with a distant or overloaded AP instead of roaming to a closer, stronger one, degrading performance.
Question 2: Which 802.11 feature helps manage sticky clients by encouraging them to roam to better APs?
- WPA3
- BSS Transition Management (802.11v) (Correct answer)
- 802.1X authentication
- WMM (Wi-Fi Multimedia)
Correct answer: BSS Transition Management (802.11v)
802.11v BSS Transition Management allows APs to send BSS Transition Request frames to suggest or force clients to roam.
Question 3: What does SNR (Signal-to-Noise Ratio) measure in a wireless network?
- The ratio of AP transmit power to client receive power
- The difference in dB between the desired signal level and the noise floor (Correct answer)
- The percentage of bandwidth used by noise traffic
- The number of clients per AP
Correct answer: The difference in dB between the desired signal level and the noise floor
SNR is the difference in decibels between the received signal and the ambient noise floor; higher SNR means better signal quality.
Question 4: What is the effect of enabling band steering on a dual-band AP?
- It disables the 2.4 GHz radio entirely
- It encourages capable clients to connect on the 5 GHz band to reduce 2.4 GHz congestion (Correct answer)
- It bonds both bands into a single channel
- It increases transmit power on both bands
Correct answer: It encourages capable clients to connect on the 5 GHz band to reduce 2.4 GHz congestion
Band steering steers dual-band-capable clients to the less congested 5 GHz band, improving overall network performance.
Question 5: A wireless client is experiencing intermittent disconnections during peak hours. What is the most likely cause?
- Incorrect DNS server settings
- AP overload due to too many associated clients or high channel utilization (Correct answer)
- Incorrect subnet mask
- DHCP pool exhaustion on IPv6
Correct answer: AP overload due to too many associated clients or high channel utilization
During peak hours, high client density and channel utilization can cause APs to drop or reject clients, leading to disconnections.
Question 6: What is the role of QoS (Quality of Service) in a wireless network?
- To encrypt wireless traffic
- To prioritize certain traffic types (e.g., VoIP, video) to reduce latency and jitter (Correct answer)
- To assign static IP addresses to clients
- To manage VLAN tagging on wired uplinks only
Correct answer: To prioritize certain traffic types (e.g., VoIP, video) to reduce latency and jitter
QoS classifies and prioritizes traffic so time-sensitive applications like VoIP and video conferencing get preferential treatment over bulk data.
CWS CWS Network Performance & Optimization 1
What is the primary cause of the 'sticky client' problem in WLANs?