CWNA-108 Exam Results

Airtime Utilization is a per-channel statistic that defines what percentage of the channel is currently being used, and what percentage is therefore free. Airtime usage can come from: Data traffic to and from client devices. Interference from WiFi and non-WiFi sources. Management overhead from APs and client devices.

The fact that is true regarding controllers and APs in a Split MAC architecture is that an IP tunnel is established between the AP and controller for AP management and control functions. A Split MAC architecture is a WLAN architecture where some of the MAC layer functions are performed by the APs (such as encryption, decryption, and frame acknowledgement) and some are performed by the controllers (such as authentication, association, roaming, and QoS). To communicate with each other, the APs and controllers establish an IP tunnel that carries the management and control frames between them. The IP tunnel can use protocols such as Lightweight Access Point Protocol (LWAPP) or Control And Provisioning of Wireless Access Points (CAPWAP). References: [CWNP Certified Wireless Network Administrator Official Study Guide: Exam CWNA-107], page 372; [CWNA: Certified Wireless Network Administrator Official Study Guide: Exam CWNA-106], page 362.

A VoIP phone is least likely to be a POE PSE of the devices listed. POE stands for Power over Ethernet, which is a technology that allows devices to receive both power and data over a single Ethernet cable. A POE PSE stands for Power Sourcing Equipment, which is a device that provides power to other devices over Ethernet. A POE PD stands for Powered Device, which is a device that receives power from a PSE over Ethernet. A midspan multi-port injector, a switch, and a midspan injector are examples of POE PSEs, as they can supply power to multiple devices over Ethernet cables. A VoIP phone is an example of a POE PD, as it can receive power from a PSE over an Ethernet cable. However, some VoIP phones can also act as POE PSEs for other devices, such as IP cameras or wireless access points, but this is not very common. References: CWNA-109 Study Guide, Chapter 8: Wireless LAN Access Points, page 2411

Cellular/LTE/5G is the best method for implementing a network backhaul for communications across the Internet in a remote area that is affected by a natural disaster. This is because cellular/LTE/5G networks are wireless and do not depend on physical infrastructure that may be damaged or unavailable in such scenarios. Cellular/LTE/5G networks also offer high-speed data transmission and wide coverage area, which are essential for emergency response operations. 802.11 bridging to the response team headquarters is not feasible because it requires line-of-sight and has limited range. Turning up the output power of the WLAN at the response team headquarters is not effective because it may cause interference and does not guarantee reliable connectivity. Temporary wired DSL is not practical because it requires installing cables and equipment that may not be available or accessible in a remote area. References: CWNA-109 Study Guide, Chapter 7: Wireless LAN Topologies, page 2031