Re: [webrtc-stats] Confusing round trip time defintion in remote-outbound-rtp (#659)

Right, so for:

> Dictionary [RTCRemoteOutboundRtpStreamStats](https://www.w3.org/TR/webrtc-stats/#dom-rtcremoteoutboundrtpstreamstats) Members

The content ought to be:

> localId of type DOMString
> 
> The localId is used for looking up the local RTCInboundRtpStreamStats object for the same SSRC.
> 
> remoteTimestamp of type DOMHighResTimeStamp
> 
> remoteTimestamp, of type DOMHighResTimeStamp [HIGHRES-TIME], represents the remote timestamp at which these statistics were sent by the remote endpoint. This differs from timestamp, which represents the time at which the statistics were generated or received by the local endpoint. The remoteTimestamp, if present, is derived from the NTP timestamp in an RTCP Sender Report (SR) block, which reflects the remote endpoint's clock. That clock may not be synchronized with the local clock.
> 
> reportsSent of type unsigned long long
> 
> Represents the total number of **RTCP Extended Report(XR) DLRR blocks received** for this SSRC.
> 
> roundTripTime of type double
> 
> Estimated round trip time for this SSRC based on the latest **RTCP Extended Report (XR)** that contains a DLRR report block as defined in [RFC3611]. The Calculation of the round trip time is defined in section 4.5. of [RFC3611]. If the latest **RTCP Extended Report (XR)** does not contain the DLRR report block, or if the last RR timestamp in the DLRR report block is zero, or if the delay since last RR value in the DLRR report block is zero, the round trip time is left undefined.
> 
> totalRoundTripTime of type double
> 
> Represents the cumulative sum of all round trip time measurements in seconds since the beginning of the session. The individual round trip time is calculated based on the DLRR report block in the **RTCP Extended Report (XR)** [RFC3611], hence undefined roundtrip times are not added. The average round trip time can be computed from totalRoundTripTime by dividing it by roundTripTimeMeasurements.
> 
> roundTripTimeMeasurements of type unsigned long long
> 
> Represents the total number of **RTCP Extended Report (XR)** blocks received for this SSRC that can derive a valid round trip time according to [RFC3611] and the above. This counter will not increment if the roundTripTime is undefined.

(Changes in bold)

I don't think I quite understand `reportsSent`. I guess it should still be SR, but how would the receiving end know how many SRs have been sent, shouldn't it say "received"?

-- 
GitHub Notification of comment by k0nserv
Please view or discuss this issue at https://github.com/w3c/webrtc-stats/issues/659#issuecomment-1231376429 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Tuesday, 30 August 2022 09:01:26 UTC