Wireless LAN Administration Version 3, rev March 2006 On This Page: Course Summary Introduction Hands-on Lab Exercises Course Outline

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Course Summary

Associated Certifications: CWNA Duration: 5 days, Classroom Availability: Find training near you. Prerequisites: Basic networking knowledge, including OSI model and IP subnetting

Introduction

The Wireless LAN Administration course, whether in an academic format or a 5-day fast-track format, provides the networking professional a complete foundation of knowledge for entering into or advancing in the wireless networking industry. From basic RF theory to 802.11 frame exchange processes, this course delivers hands on training that will benefit the novice as well as the experienced network professional.

Hands-on Lab Exercises

These are the actual labs taught in the course:

Infrastructure Mode Throughput Analysis

This lab is built around measuring WLAN throughput under various circumstances that are broken into three separate areas:

• Pure mode throughput (802.11b vs. 802.11g vs. 802.11a vs. 802.11n)
• Mixed mode throughput
• Adjacent and co-channel interference

Understanding the "speeds and feeds" of all Wi-Fi technologies is crucial to optimizing WLAN installations, applications, and good network design. This lab demonstrates the varying throughputs for Wi-Fi connectivity standards by using FTP to transfer large files from client devices to servers. You will see and compare actual throughputs of each different technology, and the impact of using mixed technologies within the same radio spectrum.

These comparisons are done using four different network architectures:

• Autonomous APs and client devices in pure mode
• Autonomous APs and client devices in mixed mode
• WLAN Controller with Lightweight APs and client devices in pure mode
• WLAN Controller with Lightweight APs and client devices in mixed mode

Co-channel and adjacent channel interference affects throughput of Wi-Fi systems dramatically. Proper network design eliminates most channel interference. The affects of channel interference are demonstrated in this exercise.

Wireless LAN Security

The Wi-Fi Alliance has standardized security mechanisms for SOHO and SMB/enterprise environments. Two distinct classes of security mechanisms exist:

• WPA compliant
• WPA2 compliant

Wi-Fi Alliance security mechanisms are only applicable at Layer 2 of the OSI model. Each of these mechanisms will be configured and tested in this lab exercise.

Other security mechanisms for WLANs exists such as VPNs (PPTP, IPSec) and secure applications (FTP/SSH, HTTPS, POP3/SSL). This lab exercise will demonstrate VPN technology using Microsoft's PPTP/MS-CHAPv2/MPPE-128 (RC4).

Site Surveying

Two specific classes of site survey methodology exist and are used in the WLAN market today:

• Manual site surveys (often called the "walkabout")
• Predictive analysis (often hailed as "the site survey method of the future")

Within each class exist two distinct categories. Manual site surveying can be categorized as either active mode or passive mode, and one or both modes can be used at any given time.

Predictive analysis software tools are based on a mathematical model of a facility blueprint and can be performed in two distinct ways. First, importing and AutoCAD (vectorized graphic) drawing allows the predictive analysis software tool to understand detailed complex layers of a facility's construction, including wall attenuation, attenuation between floors, and channel interference. Second, importing of raster graphics, such as .jpg or .bmp, allows for faster but less accurate modeling.

Neither methodology is 100% accurate, since each has its own individual weaknesses. Used together, the surveyor can create a more complete RF snapshot of any facility.

In this exercise, students will conduct both manual and predictive analysis surveying, using software and hardware tools (determined by the instructor or specific class needs).

Course Outline

The following list contains the materials covered in the lecture portion of the course:

Introduction to 802.11 WLANs Discuss the standards organizations responsible for shaping the 802.11 Wireless LAN protocol Learn how standards compliance is enforced for 802.11 WLAN vendors Examine the 802.11 standard and various amendments Discuss additional networking standards that are commonly used to enhance 802.11 WLANs Radio Frequency Fundamentals Physical aspects of RF propagation Types of losses and attenuation that affect RF communications Types of modulation used for wireless communications How channels and bandwidth are related to each other in wireless networks Three types of Spread Spectrum used in wireless networking RF Math and System Operating Margin RF units of measure Basic RF mathematics RF signal measurements Understand link budgets Define and calculate System Operating Margin (SOM) 802.11 Service Sets Explain three types of service sets defined for use within 802.11 WLANs Roaming within a WLAN Load-balancing as a method to improve congestion in WLANs

RF Power Output Regulations Understand international, regional, and local RF spectrum management organizations Understand RF channels in the unlicensed 2.4 GHz and 5 GHz frequency ranges How power output limitations are enforced by the FCC for Point-to-Multipoint (PtMP) and Point-to-Point (PtP) wireless connections Power over Ethernet Recognize the two types of devices used in Power over Ethernet (PoE) Recognize the differences between the two types of Power Sourcing Equipment (PSE) Understand the two ways in which power can be delivered using PoE Understand the importance of planning to maximize the efficiency of Power over Ethernet Wireless LAN Operation Ad Hoc networks Infrastructure networks Bridged networks Repeater networks Mesh networks WLAN switched networks Enterprise Wireless Gateway networks Enterprise Encryption Gateway networks Virtual AP networks Evolution of WLAN architectures WLAN Management WLAN Security Security Policy and Procedures Legacy 802.11 Security Components 802.11i Security Components WPA-Personal WPA-Enterprise WPA2-Personal WPA2-Enterprise Baseline Security Practices (SOHO, SMB, Enterprise)

802.11 Analysis and Troubleshooting Introduction to 802.11 Protocol Analysis 802.11 Data Frames 802.11 Control Frames 802.11 Management Frames Frame Fragmentation Power Saving operations Transmission Rates Coordinating 802.11 Frame Transmissions Differences between CSMA/CD and CSMA/CA Distributed Coordination Function (DCF) Quality of Service in 802.11 WLANS Antennas Antenna characteristics and behaviors Types of antennas commonly used with WLANs Advanced antenna systems Antenna placement and mounting Antenna safety Types of antenna cables, connectors, and accessories Site Surveying Understanding the need for a site survey Defining business requirements and justification Facility analysis Interviewing network management and users Identifying bandwidth requirements Determining contours of RF coverage Documenting installation problems Locating interference Reporting methodology and procedures Understanding specifics of each vertical market Understanding the customer's network topology Creating appropriate documentation during and after the site survey Understanding safety hazards Using appropriate hardware and software to perform the survey Understanding the need for spectrum analysis Manual RF site surveys Predictive site surveys Dense AP deployment