Experiences with Interactive Video Using TFRC
12 July 2006
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I gave
a presentation on our experiences with interactive video using TFRC
to the Datagram Congestion Control Protocol (DCCP) working group at the
66th IETF meeting in Montreal, Canada, on 12 July 2006.
In this presentation, I outlined the TFRC implementation we built as
part of the UltraGrid system, and
the challenges inherent in achieving accurate packet spacing at
the sender, and sufficiently timely feedback from the receiver. I
then highlighted the impact these have on the stability of the TFRC
protocol, especially over local-area connections with relatively short
round-trip times.
The talk also considered issues with slow-start for video, and
difficulties with matching the output rate of a codec to the
desired rate of a congestion control algorithm. One conclusion
is that window-based congestion control may be a better fit for
Internet video than rate-based congestion control.