Packet loss percentage indicates the percentage of media packets that were lost along the way. The higher the packet loss, the lower the overall media quality of the session is. testRTC shows packet loss percentage information at the top ribbon results across the various solutions available for testing and monitoring:

The packet loss values shown are split between incoming and outgoing packet loss percentage to the user or probe, as well as between audio and video. The data is averaged throughout the duration of the session.
Packet loss threshold
When the packet loss value is above a certain threshold value, it will be marked in red.
The default configuration is set to 4% packet loss. This threshold can be changed through our support.
Things you should know about packet loss
Here are a few things to remember in the back of your mind about packet loss:
- The lower the packet loss the better the media quality will be (0% packet loss is highly desirable, though not always realistic)
- WebRTC has mechanisms to overcome packet loss issues which are rather good in dealing with many of the cases, though beyond a certain percentage of packet loss, media quality degrades significantly
- Packet loss can be caused by many reasons
- Distance from a WiFi access point (the farther away, the higher the chances for packet loss)
- Cellular reception over cellular networks
- Congestion over the local network
- Congestion over the Internet
- Congestion on media servers due to poor infrastructure management
- CPU overload, causing packet loss conditions