RTCRemoteOutboundRtpStreamStats: ssrc property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.

The ssrc property of the RTCRemoteOutboundRtpStreamStats dictionary contains a positive integer value that identifies the synchronization source (SSRC) of this stream of RTP packets.

A source might be something like a microphone, or a mixer application that combines multiple sources. All packets from the same source share the same time source and sequence space, and so can be ordered relative to each other. Note that two streams with the same ssrc value refer to the same source.

Value

A positive 32-bit integer uniquely identifying the SSRC of the RTP packets whose statistics are covered by this RTCRemoteOutboundRtpStreamStats object.

The manner in which SSRC values are generated is not mandated by the specification, although it does make recommendations. You should not make any assumptions based on the value of ssrc other than that any two objects with the same ssrc value refer to the same source. See RFC 3550, section 8 for additional information about ssrc.

Note: The specification includes an example that generates values for ssrc using MD5. While not part of the standard, exactly, it is a good mechanism that may be used by some browsers; others may use other methods, such as random number generators. Do not rely upon these values meaning anything other than "these objects are associated with the same source."

Specifications

Specification
Identifiers for WebRTC's Statistics API
# dom-rtcrtpstreamstats-ssrc

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
ssrc in 'remote-outbound-rtp' stats

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

See also