RTCRemoteInboundRtpStreamStats: fractionLost property

The fractionLost property of the RTCRemoteInboundRtpStreamStats dictionary provides a value that can be used to determine the fraction of packets lost for this synchronization source (SSRC) in the last reporting interval.

To convert the value to a percentage, divide it by 256 and multiply by 100. For example, a value of 20 indicates a 7.8% packet loss.

Note that the value may not be precisely accurate due to the way that it is calculated, but it does provides a quick and convenient measure of the link quality.

Value

A number giving the fraction packet loss in the last reporting interval, multiplied by 256. The value is 0 if the calculated packet loss is negative.

Note: The value comes from the 8-bit fraction lost field of the last Sender Report (SR) or Receiver Report (RR) RTCP packet. The algorithm for calculating the value is defined in RFC 3550, Appendix A.3: Determining Number of Packets Expected and Lost.

Specifications

Specification
Identifiers for WebRTC's Statistics API
# dom-rtcremoteinboundrtpstreamstats-fractionlost

Browser compatibility

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Chrome
Edge
Firefox
Opera
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Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
fractionLost in 'remote-inbound-rtp' stats

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Full support
No support

See also