Google Alerts for "bufferbloat" pointed to this talk at Stony Brook University 
in New York State:

Dates:  Thursday, December 17, 2020 - 12:30pm to 2:00pm (US EST: UTC-5)
Location:  Zoom - contact eve...@cs.stonybrook.edu for Zoom info.

Abstract: BBR is a new congestion control algorithm and is seeing increased 
adoption especially for video traffic. BBR solves the bufferbloat problem in 
legacy loss-based congestion control algorithms where application performance 
drops considerably when router buffers are deep. BBR regulates traffic such 
that router queues don’t build up to avoid the bufferbloat problem while still 
maintaining high throughput. Though BBR is able to combat bufferbloat for 
sustained steady traffic such as large file downloads, our analysis shows that 
video applications experience significantly poor performance when using BBR 
under deep buffers. In fact, we find that video traffic sees inflated latencies 
because of long queues at the router, ultimately degrading video performance.

In this talk, I will present our work on the interaction between BBR and 
streaming video. We investigate the relationship between network metrics such 
as delay and delivery rate during the video run and the quality of subsequent 
video segments. However, we find only weak correlations, suggesting that 
another factor is at play. Our empirical investigation reveals that BBR under 
deep buffers and high network burstiness severely overestimates available 
bandwidth and is slower to converge to steady state, both of which result in 
BBR sending substantially more data into the network, causing a queue buildup. 
This elevated packet sending rate under BBR is ultimately caused by the 
router’s ability to absorb bursts in traffic, which destabilizes BBR’s 
bandwidth estimation and overrides BBR’s expected logic for exiting the startup 
phase.

Original Notice: 
https://www.cs.stonybrook.edu/Rebecca-Drucker-Research-Proficiency-Presentation-Investigating-BBR-Bufferbloat-Problem-DASH-Video


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