Motivation and proposal fo additional metrics for the StatsAPI

WebRTC Stats API
- Presenter: Varun SIngh
Co-authors:
- Rachel Huang, Roni Even, Huawei
- Dan Romascanu, Avaya
- Lingli Deng, China Monbile

Transcript

1. Considerations for Selecting RTCP Extended Report (XR) Metrics for the RTCWEB Statistics API draft-huang-xrblock-rtcweb-rtcp-xr-metrics-03 6 March 2014, IETF 89, London R. Huang, R. Even, V. Singh, D. Romascanu, L.Deng 23/03/14 1
2. Motivation F38 The browser must be able to collect statistics, related to the transport of audio and video between peers, needed to estimate quality of experience. •  W3C StatsAPI points to a stats-registry – alvestrand-rtcweb-stats-registry 23/03/14 2 ietf-rtcweb-use-cases-and-requirements
3. Interaction of W3C StatsAPI() and XR Block 23/03/14 3 Browser Browser WebRTC JS APP WebRTC JS APP RTP, RTCP SR and RR query StatsAPI() routinely RTCP XR •  Outgoing stream metrics •  Incoming stream metrics Browsers independently measure metrics for the outgoing and incoming streams
4. Changes in -02 •  Re-classify metrics into usage – Network Impact Metrics – Recovery metrics – Application Impact Metrics 23/03/14 4
5. Network Impact Metrics •  Sent, received, discarded bytes or octets –  Goodput = received-discarded •  Loss, Discard Packet Count Metric •  Burst Metric for Loss and Discard •  ECN related Metrics •  RLE for Loss and Discards 23/03/14 5
6. Application Impact Metrics •  Loss and Discard Packet Count Metric •  Sent, received, discarded octets –  Goodput = received-discarded •  Burst Metric for Loss and Discard •  Frame Impairment Summary Metrics •  Jitter buffer 23/03/14 6
7. Recovery Metrics •  Retransmitted and Post-repair count – Repaired packets <= Retx packets – Repaired in time? 23/03/14 7
8. Next Steps •  Are we missing something? •  Feedback on the list is appreciated •  Does the WG consider this as a milestone? 23/03/14 8
9. WebRTC Additional Stats draft-singh-xrblock-webrtc-additional-stats-02 6 March 2014, IETF 89, London Varun Singh, Rachel Huang, Roni Even 23/03/14 9
10. Changes in -02 version (1/2) Burst Packet Loss •  LossBurstCount   •  BurstPacketLost   – Total  number  of  packets  lost  in   bursts   23/03/14 10
11. Changes in -02 version (2/2) Burst Packet Discarded •  DiscardedBurstCount   •  BurstPacketDiscarded   – Total  number  of  packets  discarded  in   bursts   23/03/14 11
12. Burst Metrics •  Gmin = 16? [RFC3611] •  If a single burst in an interval, –  BurstCount jumps by 1 –  Difference between the new and old BurstPacket tells us packet in the burst. •  If ongoing burst across two interval, –  the BurstCount will not change –  But the BurstPacket will increase •  If multiple bursts in an interval, –  BurstCount jumps by more than 1 –  Don’t know how many total packets were lost in each burst? 23/03/14 12
13. Next Steps •  We need more input from deployments. •  Is this document useful? 23/03/14 13