TCP Congestion Control

The cluster discusses TCP congestion control mechanisms, their limitations like slow start, packet loss handling, high RTT, bufferbloat, and bandwidth delay product issues, often comparing TCP to UDP or suggesting alternatives like BBR and LEDBAT.

📉 Falling 0.4x DevOps & Infrastructure
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#8347
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Keywords

linux.die CRC F3 INET UNIX UDP OSI L4S PIE STREAMS tcp congestion packet control udp packets connection router delay latency

Sample Comments

baggy_trough Oct 8, 2020 View on HN

It's really the packet loss and TCP backoff that's a killer.

the8472 Mar 19, 2020 View on HN

netflix&co are probably using BBR to shovel data to end users which takes latency into account too, not just packet drops.

Severian Aug 10, 2023 View on HN

It's a inherit effect of TCP congestion control. TCP slow start and Window Scaling.

wkat4242 Jan 22, 2025 View on HN

Wow doesn't that make things really slow due to the RTT of the acknowledgements?

toast0 Oct 30, 2020 View on HN

Was all this TCP? You might try UDP as well, in case you're hitting a bottleneck in the tcp stack.

Locke1689 May 25, 2010 View on HN

If the current BT protocol is TCP, what makes TCP congestion control ineffective?

anilgulecha Jun 25, 2017 View on HN

You're discounting TCP ACK overhead, and time taken by switches.

DavidSJ May 22, 2012 View on HN

Your bandwidth delay product will be astronomical.

pps43 Nov 15, 2018 View on HN

There's buffering, Nagle delay, etc.

croikle Oct 28, 2013 View on HN

Bufferbloat on the upstream pipe, if somebody is using your shared connection.