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 ⁨May 2021⁩.

Thessrc property of theRTCRemoteOutboundRtpStreamStats dictionary contains a positive integer value that identifies the synchronization source (SSRC) of this stream ofRTP 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 samessrc 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 thisRTCRemoteOutboundRtpStreamStats 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 ofssrc other than that any two objects with the samessrc value refer to the same source.SeeRFC 3550, section 8 for additional information aboutssrc.

Note:The specification includes an example that generates values forssrc 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."