WebRTC Metrics
A comprehensive overview of WebRTC statistics, derived indicators, and observable signals, to better understand call quality, connectivity, and user experience in rtcStats
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inbound-rtpinboundaudiovideo
packetsLost(%)
Percentage of RTP packets lost for this SSRC.
Description
Real number; as percentage
The percentage of RTP packets lost per second for this SSRC.
For this calculation, we divide packetsLost/s by inbound-rtp.packetsReceived/s.
Interpreting Values
| Range | Description |
|---|---|
| 0% | Perfect. No packets lost |
| <0.5% | Excellent. Losses hidden by FEC/concealment |
| 0.5-1% | Acceptable for voice with FEC enabled |
| 1-2% | Noticeable degradation |
| 2-5% | Poor quality |
| >5% | Very poor |
- Video is more sensitive to loss than audio
- Audio usually has better concealment mechanisms and Opus may have FEC enabled
Common Causes
- Network congestion
- WiFi instability
- Cellular network handoffs
- ISP issues
- Overloaded local network
User Experience Impact
- Audio: robotic voice, gaps, missing syllables
- Video: blocky artifacts, frozen frames, resolution drops
- Higher loss percentage always means worse quality. The relationship is roughly linear for audio but can be more abrupt for video (a single lost keyframe can freeze the stream)
Troubleshooting
- Check if loss is bursty (causes freezes) or uniform (causes general degradation)
- Enable FEC if not already enabled
- Check if a wired connection helps - this isolates WiFi as the cause
See also
- inbound-rtp->packetsLost/s
- inbound-rtp->packetsLost
- inbound-rtp->packetsReceived