The type property of the RTCInboundRtpStreamStats dictionary is a string with the value "inbound-rtp".
Different statistics are obtained by iterating the RTCStatsReport object returned by a call to RTCPeerConnection.getStats(). The type indicates the set of statistics available through the object in a particular iteration step. A value of "inbound-rtp" indicates that the statistics available in the current step are those defined in RTCInboundRtpStreamStats.