Statistics in WebRTC Varun Singh CEO 04. 11. 2015 

Announcement ¥ 0 plan for developers 2 

http://geek-and-poke.com/ 

Why measure? 4 audio only call 

Performance Monitoring Endpoint Endpoint Middlebox MCU, SFU, TURN, … Monitor Monitor Monitor Third party Monitor Operations & Management System Implement RTCP Extension Reports http://tools.ietf.org/html/rfc6792 https://tools.ietf.org/html/draft-ietf-xrblock-rtcweb-rtcp-xr-metrics 

HTML APIs • HTMLVideoElement Extensions • http://www.w3.org/TR/2014/CR-media-source-20140717/#htmlvideoelement-extensions • droppedVideoFrames, corruptedVideoFrames, totalFrameDelay • WebRTC Statistics API • (work in progress) http://www.w3.org/TR/2015/WD-webrtc-stats-20150206/ • PeerConnection Metrics: RTP, datachannel • Transport Metrics: active and passive candidates • Security cipher suite 

Edge Stats (ORTC) Lots of data still set to zero. but encouraging to see the data 

cross browser • adapter.js is your friend 

Monitoring What? • Per-stream media quality • Transport quality • Annoyances 

What to measure? • Network metrics • bits per second, RTT, jitter, packet losses, … • Multimedia pipeline metrics • playout delay, frames metrics, … • Quality Models from metrics • Annoyances • resolution/frame rate changes, interface changes, … • failures (NATs, insufficient capacity for carrying media, …) • user feedback 10 CAVEAT: not all WebRTC applications care about the same metrics 

Low hanging fruit • Endpoint monitoring (Traffic lights) • colors to show connection is active/inactive • off/online • good/bad/ugly 

Transport Metrics 

Diagnostics • characterise an impairment? • we start with an hypothesis… • implemented as decision trees • observe how often it occurs • within a call, across calls, geographies, … • How to characterise quality of the calls? 13 

Disruptions Disruption: loss of connectivity when network interfaces change, low available capacity,or high delay The light grey vertical lines show disruption, highlighted by the red bounding boxes. 

Intermittent Disruptions 

Disruptions and user behaviour User Behaviour: The user tries to correct for the disruption by turning on and off video Zoom in to the events to view disruptions 

Endpoint Churn 25% of the conferences has some users leave and rejoin. 

Session Failure 

Annoyances Setup times: waiting for the conference to begin: NAT traversal, negotiation, etc. Note: gathering and connectivity checks can happen concurrently 

• Analytics for WebRTC • 3 lines of code —> 5 minutes. 1. include 2. initialize() —> needs registration keys 3. addNewFabric(pc, …) —> call started • optionally: send user events: audio muted/unmuted, video paused/resumed, call terminated, call held. • optionally: reportError() —> call failed to be setup due to SDP or Firewalls. • optionally: associateMstWithUserID() —> bridges using multiple media streams in a single peerconnection may want to correlate mediastream quality across endpoints. • optionally: collect and send user feedback http://www.callstats.io/api/