How to ensure Wireless LAN performance optimization should

Although many WLAN managers focus on solving problems and avoiding security vulnerabilities, Wireless LAN performance optimization is more focused on task listings. This approach is not only ill-conceived, but also ignores optimization as another factor contributing to disaster. If each AP only needs to support 10 or so users of the Internet traffic, the general performance may be acceptable, but when the AP near the maximum capacity and application requirements become higher, bandwidth consumption and bottlenecks will become very serious.





in order to optimize wireless LAN performance, network managers and administrators must use new wireless LAN measurement and testing tools that can check network performance based on the type of application running on the network. Finding these tools forces your network administrator to look for more innovative products outside of current vendors and test methods. Because these tools can be expensive, their prices may be several times higher.




Why do
need better wireless LAN performance testing and network design?





early wireless LANs are usually based on experience, using an AP coverage circumference, where the radius range represents the smallest signal strength. The site scan is then used to draw the actual signal strength and is measured in a passive (scanning) or active (associative) way. The tools used to perform the scan are manual and labor-intensive; for example, there is a method that requires testers to conduct two of measurements on the ground to collect passive and active measurement results.





It is clear that these methods do not perform well on larger wireless LANs. More importantly, they do not reflect the actual capabilities of 802.11n and an increasing variety of applications that rely on high bandwidth and low latency. By using 802.11n, transmission rates in different directions can be controlled, and a strong signal is not necessarily an acceptable indicator of application performance.





Wireless LAN performance measurement tools to determine application requirements





This is where new performance measurement tools designed specifically for 802.11n and important mobile business applications can play a significant role. For example, AirMagnet survey not only uses Iperf to measure uplink and downlink performance, but it can also be used to analyze 802.11n recommended settings and quick voice evaluations.





Veriwave Wavedeploy is an agent-based site assessment tool that generates test streams that, when sent to real-world client devices, not only measure TCP throughput, but also measure the "quality of experience" of web, voice, and video. By testing a device that uses wavedeploy, testers can generate an overlay of areas that meet the requirements of the application. This is measured by metrics for each application (for example, MOS and sound jitter).





Wireless LAN Performance Optimization: Ongoing client-side testing





optimization of Wireless LAN performance is a complex thing. After wireless LAN deployments, these new scanning tools continue to be used to verify that performance objectives have been met and to assess the impact of planning adjustments and updates. Over time, you may find that different clients have very different data rates and throughput, even if they are sending the same type of traffic from almost the same location.





For example, clients that encounter an abnormally low data rate may refuse to roam to a better AP if possible. These "tough" clients not only have low throughput, but they need more bandwidth to take time to send data of the same size. When bandwidth usage is competitive, each client is affected by the tough client. You need to use a mobile tool such as AirMagnet WiFi Analyzer, which can analyze client roaming activities, identify difficult clients, and their actual impact on application performance (e.g., MOS).





using the call time Fairness algorithm for RF measurement





periodic test results are useful for fine-tuning processes, such as disabling discovered, low data rate clients that cause problems, or enabling 802.11n options that are useful on the client. However, some performance issues are temporary and are sensitive to the client mix and location. If a visitor brings the problematic device to the office, or tries to use the wireless LAN only at a distance, a slow client will be present that drags the other client. The only effective way to deal with this type of problem is to constantly measure it through real-time responses.





Some wireless LAN vendors currently offer a "call time fair" algorithm that performs real-time RF testing and uses them to automatically adjust client transmission opportunities. For example, when aerohive dynamic Airtime scheduling is enabled, the transfer opportunity is allocated based on the amount of bandwidth that each client actually occupies. As the data rate of the client begins to drop, faster clients can get more transport opportunities to optimize overall throughput. Aerohive's performance Sentinel then associates these real-time measurements with the needs of each user and the actual throughput target. If the SLA does not meet the requirements of a large traffic load client, the NOC operator receives a compliance alert.





integrated automated and finely differentiated Wireless LAN test tools





Finally, most enterprises consolidate the use of automated/centralized and mobile/subdivision test tools and methodologies. For some tasks, it makes sense to use wireless LAN and WIPS infrastructure for uninterrupted testing and near-real-time adjustments. This approach is very effective in a large distributed network that cannot be tested regularly.





However, for other tasks, third-party or handheld tools are still very valuable. Third-party testing tools can provide a "bystander" view. Mobile tools can provide more flexibility than AP or sensor based testing. Although these tools may require additional purchase or training, they are valuable in finding vulnerabilities, debugging problems, or isolating performance issues.





Perhaps the most important thing is to avoid myopia and not always test your wireless LAN directly with the products or tools provided by your supplier. This fast-changing market will change as the company's wireless LAN applications grow.