Wireless LAN testing and troubleshooting guide

Learn how wireless LAN testing and troubleshooting tools have evolved to secure and stabilize larger, faster enterprise-class wireless networks.

Gone are the days when wireless LANs (WLANs) are used for convenient access to Web and email. Today’s WLANs act...

as a primary source of network access and they support more complex mobility services and mobile device connectivity. As a result, many companies are launching broader wireless LAN deployments that require complex WLAN testing and troubleshooting techniques to verify security, connectivity and performance. This guide provides an overview of tools designed for WLAN testing and troubleshooting.

WLAN testing for security

Businesses can no longer afford to use labor-intensive tools to query signal strength, server accessibility and Wi-Fi vulnerabilities. Testing hundreds of access points (APs) and thousands of clients geographically distributed throughout an enterprise network requires far more efficient automated tools and methods.

APs with wireless intrusion prevention systems (WIPS): Many enterprise APs can now be turned into full-time WIPS sensors when needed, and several AP vendors also offer dedicated WIPS appliances. These devices allow for full-time surveillance, watching for attacks and policy violations.

Centralized WLAN assessment tools: Organizations required to comply with regulations like PCI DSS or Federal Information Security Management Act (FISMA) will find centralized WLAN assessment tools helpful for pre-audit self-assessments. These tools can help organizations spot holes before they can be exploited.

Non-automated WLAN testing, penetration testing: While wireless penetration testing has not yet become fully automated, tools like command-line utility MDK3 and Metasploit scripts can be helpful during a penetration test.

Learn more about these and other WLAN security testing tools.

Troubleshooting WLANs

As WLANs become a primary source of network access for a diversifying workforce, manual debugging tools become impractical. Moreover, WLAN managers can’t afford  network downtime as they fix problems. So the answer now lies in easier-to-use remote WLAN management tools, backed by proactive WLAN diagnostic tests to spot and fix issues before users are impacted.

Contemporary WLAN managers: Users connecting to the WLAN from the same location may have very different outcomes depending on their device. Contemporary WLAN managers can provide nearly real-time information on a device’s connection, including click-through access to each client’s event log and basic diagnostic tools.

Distributed sensor platforms: Tools are available that use remotely deployed Wi-Fi sensors to create a distributed test platform for periodic network assurance testing.  Once connected, the sensors run defined network assurance tests and proactively alert the NOC to failures and other diagnostic data.

AP-based spectrum analysis: Capabilities differ among AP-based spectrum analysis tools, but at a basic level, they use APs to listen for non-802.11 interferers, such as video cameras and phones. Some even apply signatures to classify interferers. Read this article to learn about spectrum analyzer Cisco CleanAir.

Learn more about WLAN troubleshooting tools.

WLAN performance testing

Older wireless LAN performance testing and network design methods do not scale well to today’s larger wireless LANs. More importantly, the methods don’t reflect the realities posed by 802.11n and more diverse applications that depend on high bandwidth and low latency. This is where new performance tools designed specifically for 802.11n and important business mobility applications can be a big help.

WLAN performance measurement tools: Today’s WLAN performance measurement tools measure uplink and downlink performance and analyse measurements to offer 802.11n recommendations. Other tools generate test streams to real client devices to measure the quality of experience for Web, video and voice.

Client survey tools: Periodic use of client survey tools can help verify that performance targets continue to be met. They can also assess the impact of network changes and updates. For example, they can analyse client roaming behaviour to identify sticky clients and their impact on application behaviour.

Airtime fairness algorithms for RF measurement: Some WLAN vendors now offer proprietary "airtime fairness" algorithms that take real-time RF measurements and use them to automatically adjust client transmit opportunities. As a client's data rate starts to fall, faster clients can be given more transmit opportunities, optimizing total throughput.

Learn more about WLAN performance testing tools.

About the author: Crystal Bedell is an award-winning writer and editor specializing in technology. Her articles, tips and guides help IT professionals evaluate technology, secure and modernize their IT infrastructure, solve business problems and prepare for IT certifications. She can be reached at [email protected].

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