Adaptive FEC for RMCAT CC

Varun Singh, Marcin Nagy, Jörg Ott, Lars Eggert.
IETF 90, Toronto.

Transcript

1. Adaptive FEC for Congestion Control Varun Singh, Marcin Nagy, Jörg Ott, Lars Eggert IETF 90, Toronto, 24. July 2014 tools.ietf.org/html/draft-singh-rmcat-adaptive-fec-00
2. IPR •  Lars made a 3rd party disclosure: – https://datatracker.ietf.org/ipr/2394/ – Also sent to the mailing list
3. Error Resilience NACK (RTX) RPS SSA UEP 3G Link Packet Loss End-to-End Delay
4. RTCP Interval time Throughput media rate FEC STAY state! PROBE state! STAY state! STAY state! UP state! UP state! DOWN state! PROBE state! (A) Adding FEC (B) Swapping FEC with media (C) Partially swapping FEC with media Available Capacity CONCEPT
5. CC Framework Media Encoder Rate Controller RTP Packets Transport Layer (UDP) IP Source RTP RTCP FB Pacing Buffer
6. RFC 6363: FEC Framework Media Encoder Rate Controller RTP Packets FEC Code FEC Module RTP (De)mux Transport Layer (UDP) IP Repair RTP RTCP FB Source RTP
7. State Machine STAY UP DOWN PROBE Good conditions, probe network No more bandwidth available Stable conditions Stable conditions Unstable conditions Unstable conditions Unstable conditions STEADY PROBE DECREASE INCREASE
8. FEC Scheme •  Open Issue – Leave it open i.e., generic – Or, RF5109 (ULP), RFC6015 (1-d interleaved), parity, 1- or 2-d interleaved XOR, Reed-Solomon, … – There was discussion in RTCWEB on FEC Schemes. S, Holmer, et al., "Handling  Packet  Loss  in  WebRTC", Proc. of IEEE International Conference on Image Processing (ICIP 2013) , 9 2013.
9. RTCP Feedback •  RLE of Post-repair (RFC5725) •  RLE of loss packets (RFC3611) •  RLE of discarded packets (RFC7097) •  Packet count of lost and repaired packets – (draft-ietf-xrblock-post-loss-repair)
10. Applicability •  Implemented over a delay-based congestion control – See paper for details •  However would like to generalize it. – Apply to SCReAM, GCC, … Nagy M., Singh V., Ott J., Eggert L., Congestion  Control  using  FEC  for  Conversational  Multimedia   Communication, Proc. of ACM Multimedia Systems, Singapore, SG, Mar, 2014,
11. Next steps •  Code: (coming soon) –  https://github.com/protocols-comnet/rmcat-adaptive-fec-code •  Evaluation Paper: –  Nagy M., Singh V., Ott J., Eggert L., Congestion Control using FEC for Conversational Multimedia Communication, Proc. of ACM Multimedia Systems, Singapore, SG, Mar, 2014, •  Initial comments received from Ingemar Johansson –  More feedback is appreciated J
12. Evaluation (1/3) •  Ns-2 simulation, Variable link capacity, Single flow on the link 0 50 100 150 200 250 300 350 400 0 100 200 300 400 500 600 700 800 900 Throughput [kbps] Time [s] OWD: 50ms
13. Evaluation (2/3) 0 100 200 300 400 500 600 700 800 900 Time [s] OWD: 100ms
14. Evaluation (3/3) 0 100 200 300 400 500 600 700 800 900 Time [s] Link capacity FBRA FEC probe rate OWD: 240ms
15. Compete with short TCPs 0 100 200 300 400 500 600 700 800 900 Time [s]
16. TESTBED Evaluation (1/2) •  1Mbit/s link capacity, 50ms one-way-delay, Two RTP flows on the link 0 200 400 400 200 0 0 50 100 150 200 250 300 350 400 0 40 40 0 Throughput [kbps] PSNR [dB] Time [s] FBRA Call1 FBRA Call2 PSNR Call1 PSNR Call2
17. TESTBED Evaluation (2/2) 0 200 400 400 200 0 0 50 100 150 200 250 300 350 400 0 40 40 0 Throughput [kbps] PSNR [dB] Time [s] FBRA Call1 FBRA Call2 PSNR Call1 PSNR Call2 •  1Mbit/s link capacity, 100ms one-way-delay,