Published: 23 Jan 2013
When it comes to creating a bring your own device (BYOD) plan, many IT shops focus on security and access policy, but wireless LAN troubleshooting can be just as crucial. After all, the more diverse the array of Wi-Fi devices in the workplace, the greater the impact on the enterprise wireless LAN. The good news is that there are a variety of tools that network administrators can use for proactive and responsive BYOD troubleshooting.
Why Personal Devices Are a Nightmare For WLAN Troubleshooting
Embracing BYOD in the enterprise may reduce equipment costs, but contrary to popular belief, it doesn't necessarily cut operating expenses.
In fact, personal devices can drain the network and place a strain on IT staff. In a survey recently conducted by Fluke Networks, 52% of organizations said they receive daily complaints about BYOD WLAN issues, most related to slow or dropped connections. These problems frustrate BYOD users, but worse, they slow down the WLAN. After all, misbehaving devices increase competition for scarce spectrum. As a result, IT spends more time responding to trouble tickets, diagnosing reported problems and reconfiguring devices or the WLAN itself.
Proactive BYOD WLAN Troubleshooting Tactics
Many BYOD-induced network issues are exacerbated by a reactive troubleshooting approach that focuses on fixing problems after the fact. Yet a proactive strategy that anticipates BYOD needs and behaviors can help the network team respond more quickly to early signs of trouble and may reduce total cost of operation.
The first step to avoiding BYOD troubles is to understand what you’re up against. BYODs are by definition an unknown, ever-changing set of devices. As such, it’s essential to detect and determine the types of devices competing for corporate airspace and then run diagnostics to see how the network is supporting these clients. It may also be necessary to block certain devices.
All enterprise WLAN products can report on connected Wi-Fi clients and fingerprint these clients. Therefore network admins can see exactly how many unique iPads connected last month, for example. You many need a Wireless Intrusion Protection System (WIPS) to spot BYOD clients that interfere but don’t connect, however. These can include personal hotspots and gadgets that communicate via Wi-Fi Direct.
Once you harness BYOD awareness, the next step is to differentiate between devices that should be embraced and those that must simply be tolerated. For example, if streaming media clients like Apple TVs are discovered gobbling WLAN bandwidth without business purpose, you may wish to proactively locate and block those unauthorized BYODs.
Spectrum And Performance Testing For The BYOD WLAN
More on WLAN troubleshooting
WLAN testing: Wireless intrustion prevention systems and centralized testing tools
Sustaining WLAN performance for the video explosion
How to ensure WLAN performance optimization
Optimizing the WLAN for real-time applications
Once you've decided which personal devices you will support, using a series of tactics can ensure they're optimized on the network.
WLAN planners can help predict the network impact of these personal devices. They allow you to use “what-if” analysis to identify access points (APs) and bands/channels that will become overloaded as the BYOD population grows, and take steps to increase capacity or reallocate spectrum to head off congestion.
In addition, WLAN site survey tools can be used to find and fix weak coverage areas. For example, if many employee-owned iPads are connecting to your WLAN, you can conduct a site survey with an iPad to find and fix weak coverage areas for those devices. Site survey tools can also measure actual application performance for BYOD devices (in upstream and downstream directions) throughout desired coverage areas. Active site surveys are critical for diverse consumer-grade BYODs that behave quite differently than enterprise laptops. For example, some of these devices roam less aggressively or generate more bi-directional traffic. Getting a handle on BYOD behavior can help you head off problems and recognize root causes when troubles occur.
WLAN analyzers, spectrum analyzers and wireless intrusion prevention systems (WIPS) can also help identify and measure the network impact of both tolerated devices and clients you wish to block. For example, when searching for unwanted devices, you may find that some products prefer certain bands or channels. With this information, you can adjust enterprise WLAN settings to reduce interference and improve performance for authorized clients in those areas. In addition, testing can be used to develop WIPS rules to auto-block banned BYODs; for example, letting a smartphone connect to your enterprise WLAN but preventing it from behaving as a personal hotspot.
Reactive WLAN Troubleshooting Is Still Relevant For BYOD
While proactive troubleshooting can reduce BYOD challenges and prevent network drain, reactive troubleshooting using spectrum analysis and other testing tools can address problems that are impossible to predict.
Traditional portable WLAN analyzers and spectrum analyzers will always be needed for on-site diagnostics, but they don’t have to be the first or only tools in your toolbox. A growing number of enterprise WLAN and WIPS products now provide integrated spectrum analysis, enabling administrators to detect and fingerprint interferers from afar. Similarly, some enterprise APs and WIPS sensors can be remotely configured to temporarily enter Radio Frequency Monitor (RFMON) mode and/or capture packets. These tools can speed diagnosis when problems are detected and even diagnose intermittent troubles caused by transient BYODs.
Remote WLAN connectivity tests executed by WIPS sensors can also be helpful. These tools turn WIPS sensors into Wi-Fi clients, attempting to connect to each defined SSID and send test traffic to specified IPs and ports. Scheduled connectivity tests run at regular intervals can help you notice when BYOD competition starts to degrade authorized client performance. On-demand connectivity tests can measure actual BYOD impact during remote troubleshooting.
Finally, the need for network troubleshooting can also be reduced by taking full advantage of enterprise WLAN radio resource management capabilities, including automated channel selection, interference avoidance, band steering, load sharing and proprietary optimizations that cater to faster clients. These capabilities detect and respond to emerging troubles in real-time, before users are impacted.
About the author:
Lisa Phifer owns Core Competence Inc., a consulting firm specializing in business use of emerging Internet technologies. Lisa has been involved in the design, implementation and evaluation of internetworking, security and management products for 30 years.
- Myth vs. Reality: Cloud-Managed Wireless LAN and the Primary Access Network –SearchSecurity.com
- Wireless network management: Expert tip –Cisco Systems, Inc.
- Ensuring an Optimal Wi-Fi Experience: Best Practices –SearchSecurity.com
- E-Guide: Wireless LAN access control: Managing users and their devices –SearchSecurity.com