Example use case: Troubleshooting an intermittent WiFi performance issue

Introduction

A friend was experiencing intermittent poor network performance with their 2.4GHz wireless network. This was causing issues with activities such as video streaming. I took the following steps to resolve the issue which included using the Network Performance Monitor to track network performance before and after changes to the network were made.

Confirming the issue

I rebooted the wireless router and ran a few ad hoc speedtests using my smartphone; the results seemed normal so I installed the Network Performance Monitor to collect performance data for a couple of days.

The daily reports generated by the system confirmed a performance issue: overall slow speeds, sometimes near zero Mbps with occasional spikes to higher speeds. The average transmit speed was 4.5 Mbps. Here is a performance graph illustrating the poor network performance:

Network performance graph before configuration changes

Looking for a root cause

Using a WiFi scanning app on my phone I found a large number of 2.4GHz wireless networks in the area; my friend lives in a large apartment building so this was to be expected.

I then checked the wireless network configuration and found that the 2.4GHz network channel width was set to 40MHz. Suspecting that the wireless network was experiencing high interference due to its wide channel setting I reduced the channel width to 20MHz and moved the wireless network to a channel with fewer competing networks.

Measuring the effects of the configuration changes

I left the Network Performance Monitor in place to track performance with the revised network settings. The performance improvement was very noticeable; here is the performance graph for the day I applied the configuration changes:

Network performance for the day changes were applied

The changes were applied between 6pm and 7pm which correlates with the sudden improvement in performance seen on the graph.

The graph for the following day shows that the performance improvement was consistent; the average transmit speed with the revised network configuration was 41 Mbps:

Network performance graph for the following day

Conclusion

Using the Network Performance Monitor allowed me to confirm an intermittent network performance issue and to measure the effects of configuration changes applied to the network.

I was able to measure the performance improvement which increased by a factor of 9x from an average transmit speed of 4.5 Mbps to an average of 41 Mbps.