Re: Review of WebRTC Statistics from Web Performance Working Group

Hi Stefan.

On Wed, Dec 14, 2016 at 1:29 AM, Stefan Håkansson LK <
stefan.lk.hakansson@ericsson.com> wrote:

> Dear Web Performance Working Group,
>
> The WebRTC Working Group is working toward publishing its WebRTC
> Statistics API to Candidate Recommendation and is thus seeking review
> from a variety of groups on the document:
>
> https://www.w3.org/TR/2016/WD-webrtc-stats-20161214/
>
> We are particularly interested on feedback from the Web Performance
> Working Group on possible alignments needed between the names, value
> spaces and design of the statistics exposed in our documents with the
> ones the Web Performance Working Group has brought through its various
> APIs.
>

On a quick scan, I didn't spot any substantive problems. That said, a few
nitpicks and thoughts:

   - Provide a normative reference [1] for DOMHighResTimeStamp? Want to
   make sure that time origin definitions are aligned across implementations.
   - Stats are associated with each stream, which means that application
   developers have to manually instrument each stream. Is there a use case for
   analytics / third-party instrumentation to gather similar stats? E.g. it
   would be nice if existing RUM providers could auto-gather stats without
   monkey-patching all the WebRTC APIs to figure out when new streams are
   initiated, etc.
      - Performance Timeline provides PerformanceObserver [2] interface
      which allows anyone to register and listen for events. It might be worth
      considering, if it makes sense, emitting some WebRTC related events via
      this mechanism... which could stream specific or aggregated.

I'd be curious to hear from RUM vendors/folks if and how they currently
instrument WebRTC.

Cheers.
ig

[1] https://www.w3.org/TR/hr-time-2/#dom-domhighrestimestamp
[2]
https://www.w3.org/TR/performance-timeline-2/#the-performanceobserver-interface