How to recognise it
Calls stutter or games lag when someone starts a download, upload or big video stream, then recover when it stops. In a WiFi Ping result, you will see loaded latency far above idle latency, for example 15 ms idle but 200 ms while downloading.
Why it happens
Networking equipment has buffers to absorb bursts. When those buffers are very large and the link is full, packets sit in line for a long time. The line is busy but responsiveness collapses. It affects every kind of connection, but is most noticeable on slower uplinks.
How to fix it
The standard fix is Smart Queue Management (SQM), using algorithms such as fq_codel or CAKE. Many modern routers offer it under names like SQM, Smart Queue, QoS or Adaptive QoS.
- Enable SQM or a similar feature on your router if available
- Set the limits to about 90 to 95 percent of your real speeds so the queue forms on your router, where it is managed
- Test again and compare loaded latency before and after
- If your router lacks the feature, a compatible replacement or third-party firmware can add it
How WiFi Ping helps
WiFi Ping measures latency while your connection downloads and while it uploads, and rates the increase. Run the test before and after a change, save both, and use Compare My Connection to see the improvement.