Certified Wireless Technology Administrator - Chapter 3 - Wireless LAN Infrastructure Devices

Layer 1 and Layer 2

Access points work at which layers of the OSI model? Choose 2. A. Layer 1 B. Layer 2 C. Layer 3 D. Layer 4 E. Layer 5 F. Layer 6 G. Layer 7

virtual local area networks or VLANs

Allows an administrator to separate physical ports into logical networks to organize traffic. Defines broadcast domains in a Layer 2 network by inserting membership information into Ethernet frames. Layer 2 Ethernet switches can create broadcast domains based on how the switch is configured by using this technology.

IEEE 802.3at

Also known as PoE+, this amendment to the IEEE 802.3 standard was ratified in 2009 with higher power levels and improved power management information. Allowcates 25.5 watts (W) of power per port maximum

centralized data forwarding architecture

Also known as split-MAC architecture, this design separated the intelligence from the access point and placed it into the wireless controller to allow for centralized management and control of the wireless network. Can cause bottlenecks in overloaded or poorly designed networks. With 802.11n, the aggregate throughput could be too much for the network to handle, resulting in poor performance.

IEEE 802.11r

Amendment to IEEE 802.11 for fast transition or FT

IEEE 802.11s

Amendment to IEEE 802.11 for including wireless mesh networking ratified in 2011.

IEEE 802.11w

Amendment to IEEE 802.11 for management frame security

IEEE 802.11e

Amendment to IEEE 802.11 for quality of service.

static output transmit power

An access point model that the transmit output power cannot be adjusted, which will limit your ability to decrease or increase the size of the radio frequency cell.

Dynamic Host Configuration Protocol or DHCP Server

Automatically issues an Internet Protocol or IP address (logical address) to allow upper-layer communication between devices on the network. IP addresses are a function of Layer 3 of the OSI model.

classification signature

Determines the maximum amount of power a device requires, thereby allowing the PSE to better manage the amount of power delivered to a specific port.

WPA 2.0 support, RADIUS server, and Repeater mode

Enterprise access points may contain which of the following features? Choose 3. A. WPA 2.0 support B. RADIUS server C. Static output power D. Repeater mode E. Power sourcing equipment

wireless repeater

Extends the size of the radio frequency cell, so that devices not in hearing range of an access point can connect to the wireless network. However, the cost is reduced throughput for other devices accessing the network through this. Layer 2 device. For security purposes, the Ethernet port on a wireless repeater should be disabled since it is not connected to an infrastructure.

wireless bridge

For wireless point-to-point or point-to-multipoint configurations connecting two or more LANs together. Benefits include cost savings and high data transfer rates compared to some other connectivity options. Security and environmental conditions to take into consideration.

Wireless Intrusion Prevention or WIPS

Helps determine and has the potential to mitigate certain levels of wireless intrusions or attacks on the network. An example is the detection of a rogue access point.

About 50%.

How much is data throughput reduced when using a wireless repeater?

Two-way communication one way at a time

In computer network terminology, the definition of half duplex is closest to which of the following? A. One-way communication only B. One-way communication one way at a time C. Two-way communication both directions simultaneously D. Two-way communication one way at a time

infrastructure mode

In this operation mode, all wireless data traffic is passed through the access point to the intended destination, whether that is a file server, a printer, the Internet, or anything else.

midspan device

Injects the required DC voltage (48V nominal) into the Ethernet cable allowing the AP, bridge, or other powered device to receive electrical power and computer data. There are two types of these devices — single-port injectors and multiport injectors.

DC power to the end device

Power sourcing equipment delivers which of the following? A. RF power to the access point B. DC power to the end device C. RF power to an antenna D. DC power to an antenna

IEEE 802.3-2005 clause 33 or 802.3af

Ratified amendment to the IEEE 802.3 standard released in 2003, regarding Power over Ethernet. Allocates 15.4 watts (W) of power per port maximum.

distributed data forwarding architecture

Reduces the amount of infrastructure traffic because the controller-based access point is able to make more decisions, taking some of the load away from the wireless controller. Applies to cooperative / controllerless architecture.

HTTP and HTTPS

SOHO access points are typically configured by using __________ and ________________. Choose 2. A. HTTP B. FTP C. HTTPS D. CLI E. SMTP

WPA 2.0 support, Static output power, and Wi-Fi certifications

SOHO access points commonly support which of the following features? Choose 3. A. WPA 2.0 support B. CLI configuration C. Static output power D. Wi-Fi certifications

wireless residential gateway

SOHO or home broadband routers that are usually equipped with an Internet port, several ports for Ethernet switches, and a wireless access point. Features can include NAT, DHCP server, IP routing, DNS services, and firewall

Power over Ethernet or PoE

Sends direct current (DC) voltage and computer data over the same Ethernet cable, enabling a device to receive DC power and computer data simultaneously. This eliminates the need for an external alternating current (AC) power source to be near the Ethernet device.

15 dBm

Static output transmit power of a SOHO access point is typically: A. 32 dBm B. 15 dBm C. 23 mW D. 15 mW

endpoint device

Supplies DC power and computer data directly at the Ethernet port rather than relying on an intermediate device to supply the power. Wireless LAN controllers and Ethernet switches are examples of these devices.

centralized administration

This gives an administrator complete control over the wireless network from a single location. Unlike autonomous access points that require intervention at each device for configuration, a wireless LAN controller can be a "one-stop shop" for configuration and management of the wireless network.

False

True or False: SOHO access points typically offer configuration from the command line interface or CLI.

False

True or false: A benefit of a wireless LAN controller is distributed administration.

False

True or false: An administrator should always configure an access point from the wireless network.

half-duplex

Two-way communication that occurs in only one direction at a time. Wireless access points operate in this way.

distribution system or DS

Typically an Ethernet segment or Ethernet cable.

root access point mode

Typically the default operation mode in which an enterprise-grade access point is set and involves connecting the access point to a distribution system or DS such as an Ethernet segment, wireless distribution system or WDS, or network infrastructure.

Autonomous, controller-based, and cooperative.

What are the three common types of wireless access points or WAPs?

It is defined in 802.3-2005 Clause 33, also known as IEEE 802.3af, and IEEE 802.3at, sometimes called PoE+

What are the two ratified amendments to the IEEE 802.3 standard for Power over Ethernet (PoE)?

328 feet or 100 m.

What is the maximum length of an Ethernet cable as defined by the IEEE 802.3 standard?

15.4 W maximum power per port

What is the maximum power per port as defined in IEEE 802.3-2005 clause 33 or 802.3af?

25.5 W maximum power per port

What is the maximum power per port as defined in IEEE 802.3at?

48 VDC although amendments allow range of 36 - 57 VDC

What is the nominal voltage for Power over Ethernet or PoE?

SOHO access points are configured via a web browser, using either HTTP or Hypertext Transfer Protocol, or HTTPS or Hypertext Transfer Protocol Secure.

What is the typical user interface for a SOHO access point?

Layer 3 or the Network Layer

What layer of the OSI model are Internet Protocol or IP addresses a function of?

autonomous access points

Wireless access points that are self-contained units with all the intelligence necessary to provide devices with wireless access to a wired network infrastructure and access to the resources the devices have permission to use. Two popular types of this access point are small-office home-office or SOHO and enterprise.

The same SSID and the same RF channel

Wireless bridges must be configured with _______ and __________. Choose 2. A. A null SSID B. The same SSID C. The same RF channel D. Channel scanning E. Wired Equivalent Privacy

wireless network management system or WNMS

A centralized tool to manage autonomous access points. They can be used to help scale the autonomous access point architecture but are not required.

Remote Authentication Dial-In User Service or RADIUS

A common feature of wireless LAN controllers is a built-in user database for 802.1X/EAP authentication. It allows a network administrator to utilize the most advanced security features available today to secure the wireless network

Direct connectivity

A controller-based access point connected to a port on the wireless LAN controller and not to an intermediate device is considered to have which of the following? A. Direct connectivity B. Distributed connectivity C. Decentralized connectivity D. Centralized connectivity

wireless LAN controllers

A main component in many wireless LAN deployments. They range from branch office models with a few controller-based access points to large-scale enterprise devices with hundreds or even thousands of controller-based access points.

wireless mesh

A network where all nodes connect together with at least two paths for every node. This allows for reliable communication in the event of a device or path failure. Popular outdoors and commonly uses the 2.4 GHz ISM band for device access and the 5 GHz UNII band for mesh device connectivity.

Autonomous

A self-contained intelligent access point is: A. Controller-based B. Heavyweight C. Autonomous D. Thin

wireless distribution system or WDS

A system enabling the wireless interconnection of access points in an IEEE 802.11 network. It allows a wireless network to be expanded using multiple access points without the traditional requirement for a wired backbone to link them. The notable advantage of it over other solutions is that it preserves the MAC addresses of client frames across links between access points.

controller-based access points

A wireless access point or WAP that can function in conjunction with the wireless LAN controller and not as a standalone device. They contain less intelligence and are centrally managed from the wireless LAN controller. Cost significantly less.

cooperative access points

A wireless access point or WAP that provides a wireless infrastructure without the use of a hardware controller. Intelligence in each device but controlled by cloud. They are "adoptable" by a controller in a large enterprise environment. Scale well.

48

The 802.3-2005 Clause 33 standard specifies VDC as the nominal voltage. A. 32 B. 57 C. 48 D. 12

cell

The area of radio frequency coverage of a wireless access point.

power sourcing equipment or PSE

The device that supplies the DC voltage to the end devices that receive the DC power in Power over Ethernet or PoE.

service set identifier or SSID

The logical name or identifier that all devices connected to the access point will share.

powered device or PD

The receiver of the DC power in Power over Ethernet or PoE such as an AP, bridge, IP camera, or IP phone.

enterprise access points

These access points typically have a much more extensive feature set than the SOHO access points including adjustable output transmit power, command-line interface configuration, outdoor use, plenum ratings, industrial environment ratings, more memory, and faster processors to help handle the load and various environmental conditions.

SOHO access point

These access points usually have a less extensive feature set than enterprise-grade access points, are best used in the home environment and usually have a limited number of connections for computers and devices.

wireless LAN routers

These are also known as a wireless broadband router or wireless residential gateways, In the enterprise environment, it has similar functionality plus extended features and is known as a wireless VPN router.

redundancy

This allows for fault-tolerant deployments and provides uninterrupted access in the event an access point or wireless LAN controller fails. If complete, it will prevent a major outage caused by hardware failure for mission-critical or other deployments.

wireless branch router

This compact and portable device is used to extend a corporate network to a remote location such as a home, conference room, or branch office through a secure connection using a WAN or the Internet. Offers Layer 3 VPN tunnels between devices and the router on each side that acts as a VPN endpoint or pass-through. PPTP, L2TP/IPsec, SSH2, advanced IP services, edge router capability.

Root access point mode

Which access point mode involves connecting the access point to a distribution system for user access to the LAN? A. Bridge only mode B. Repeater only mode C. Root access point mode D. Access mode

Layer 2

Which layer of the OSI model is responsible for delivering data to a unique hardware address? A. Layer 1 B. Layer 2 C. Layer 3 D. Layer 4 E. Layer 5 F. Layer 6 G. Layer 7

Centralized administration, Captive portal, and Built-in RADIUS services

Wireless LAN controllers may contain which of the following features? Choose 3 A. Centralized administration B. Captive portal C. Network Address Translation (NAT) D. Built-in RADIUS services E. IP routing

Single-port injectors and Multiport injectors

Which of the following are midspan PoE devices? Choose 2. A. Single-port injectors B. Multiport injectors C. Endpoint injectors D. Endspan injectors

Midspan

Which of the following devices is an in-line device that will inject DC voltage into the Ethernet cable? A. Midspan B. Midpoint C. Endspan D. Endpoint

Larger cell size allows more devices to access the medium and extends cell size

Which of the following is a benefit of a wireless repeater? Choose 2. A. Higher data transfer rate B. Larger cell size allows more devices to access the medium. C. Smaller cell size allows fewer devices to access the medium. D. Less data throughput E. Extends cell size

Virtual local area networks (VLANs) involve a logical separation of ports.

Which of the following statements is true regarding a wireless LAN controller? A. Virtual local area networks (VLANs) involve physical separation of ports. B. Virtual local area networks (VLANs) involve a logical separation of ports. C. Virtual local area network (VLAN) is another name for a repeater. D. Virtual local area networks (VLANs) require Power over Ethernet (PoE).