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

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