Mihail Yanev, Stephen McQuistin, and Colin Perkins
Proceedings of the Workshop on Network and Operating System Support for Digital Audio and Video (NOSSDAV),
June 2022.
DOI:10.1145/3534088.3534347
This Work has been Retracted by ACM at the request of the authors.
The authors notified ACM that they found a bug in their experiments.
This bug caused the control case, TCP New Reno without the new
congestion window validation algorithm, to incorrectly reset its
slow-start threshold after an idle period. The resulting code was
inconsistent with both the TCP specification and the standard Linux
TCP implementation and would overshoot the intended sending rate
causing a burst of packet loss. The results for the algorithm under
test, TCP with new congestion window validation, were correct, but
did not provide the benefits claimed compared to the corrected
control.
When using HTTP adaptive streaming, video traffic exhibits on-off
behaviour with frequent idle periods that can interact poorly with
TCP congestion control algorithms. New congestion window validation
(New CWV) modifies TCP to allow senders to recover their sending rate
more quickly after certain idle periods. While previous work has
shown that New CWV can improve transport performance for streaming
video, it has not been shown if this translates to improved application
performance in terms of playback stability. In this paper, we show that
New CWV can reduce video re-buffering events by up to 4%, and limit
representation switches by 12%, without any changes to existing rate
adaptation algorithms.
Download: yanev2022newcwv.pdf