RTCRemoteInboundRtpStreamStats: localId property

A string which can be compared to the value of an RTCOutboundRtpStreamStats object's remoteId property to see if the two represent statistics for each of the two sides of the same set of data sent by the local peer.

You can think of the local and remote views of the same RTP stream as pairs, each of which has a reference back to the other one. Thus, if an RTCStatsReport includes an remote-inbound-rtp statistics object (of type RTCRemoteInboundRtpStreamStats), it should also have a corresponding outbound-rtp object.

Both of these provide information about the same batch of packets being sent from the local device to the remote peer. The difference is that outbound-rtp offers statistics about the outgoing data from the local peer's perspective, while remote-inbound-rtp provides statistics about the same data from the perspective of the remote peer, as it is received.

See the example in RTCRemoteOutboundRtpStreamStats.localId. This shows how to correlate statistics about data sent from the remote peer (from the perspective of the remote peer) with the incoming data from the perspective of the local peer.

The code to correlate send data from the perspective of the local peer and received data from the perspective of the remote peer would be almost the same, and can be inferred from that example.