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Lliorayesterday at 2:48 PM1 replyview on HN

Ship-to-shore SAT link, 800 ms RTT, 2 % burst loss. We muxed 4 K pps telemetry + 1 Mbps H264 over QUIC last year. Head-of-line blocking vanished - TCP would have stalled 12 s on each 200 ms fade. FEC at the stream frame, not packet, let us ride fades with 3 % overhead. QUIC’s real win is acking individual frames; we saw 40 % better goodput vs TCP + application FEC at the same latency.


Replies

scottlambyesterday at 3:20 PM

Very cool result, but I'm struggling to understand the baseline: what does "TCP + application FEC" mean? If everything is one TCP stream, and thus the kernel delivers bytes to the application strictly in order, what does application FEC accomplish? Or is it distributed across several TCP streams?