Adaptive FEC for Congestion Control Var arun Sing un Singh, - - PowerPoint PPT Presentation

▶

Dec 03, 2022 94 likes •281 views

Adaptive FEC for Congestion Control Var arun Sing un Singh, Marcin Nagy, Jrg Ott, Lars Eggert IETF 90, Toronto, 24. July 2014 tools.ietf.org/html/draft-singh-rmcat-adaptive-fec-00 IPR Lars made a 3 rd party disclosure:

SLIDE 1

Adaptive FEC for Congestion Control

Var arun Sing un Singh, Marcin Nagy, Jörg Ott, Lars Eggert IETF 90, Toronto,

24. July 2014

tools.ietf.org/html/draft-singh-rmcat-adaptive-fec-00

SLIDE 2

IPR

Lars made a 3rd party disclosure:

– https://datatracker.ietf.org/ipr/2394/ – Also sent to the mailing list

SLIDE 3

Error Resilience

NACK (RTX) RPS SSA UEP 3G Link Packet Loss End-to-End Delay

SLIDE 4

RTC TCP P In Inter terval val

time Throughput

media ra media rate te FEC FEC STAY state PROBE state STAY state STAY state UP state UP state DOWN state PROBE state (A) (A) Adding FEC dding FEC (B) (B) Swapping g FEC with media FEC with media (C) (C) Par artiall tially y swapping swapping FEC with media FEC with media Available Capacity

CONCEPT

SLIDE 5

CC Framework

Media Encoder Rate Controller RTP Packets Transport Layer (UDP) IP Source RTP RTCP FB

Pacing Buffer

SLIDE 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

SLIDE 7

State Machine

STAY UP DOWN PROBE Good conditions, probe network No more bandwidth available Stable conditions S t a b l e c

d i t i

s U n s t a b l e c

d i t i

s Unstable conditions Unstable conditions

STEADY PROBE

DECREASE INCREASE

SLIDE 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

n Image Processing (ICIP 2013) , 9 2013.

SLIDE 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)

SLIDE 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,

SLIDE 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

SLIDE 12

Evaluation (1/3)

Ns-2 simulation, Variable link capacity, Single flow on the link

50 100 150 200 250 300 350 400 100 200 300 400 500 600 700 800 900

Throughput [kbps] Time [s]

OWD: 50ms

SLIDE 13

Evaluation (2/3)

100 200 300 400 500 600 700 800 900

Time [s]

OWD: 100ms

SLIDE 14

Evaluation (3/3)

100 200 300 400 500 600 700 800 900

Time [s]

Link capacity FBRA FEC probe rate

OWD: 240ms

SLIDE 15

Compete with short TCPs

100 200 300 400 500 600 700 800 900

Time [s]

SLIDE 16

TESTBED Evaluation (1/2)

1Mbit/s link capacity, 50ms one-way-delay,

Two RTP flows on the link

200 400 400 200 50 100 150 200 250 300 350 400 40 40

Throughput [kbps] PSNR [dB] Time [s]

FBRA Call1 FBRA Call2 PSNR Call1 PSNR Call2

SLIDE 17

TESTBED Evaluation (2/2)

200 400 400 200 50 100 150 200 250 300 350 400 40 40

Throughput [kbps] PSNR [dB] Time [s]

FBRA Call1 FBRA Call2 PSNR Call1 PSNR Call2

1Mbit/s link capacity, 100ms one-way-delay,