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QUIC fundamentally competes on a different level because TCP is broken for modern networks. From a network usage standpoint, there isn't anything "unfair" abou
by trevyn 9y ago
QUIC fundamentally competes on a different level because TCP is broken for modern networks.
From a network usage standpoint, there isn't anything "unfair" about it -- QUIC runs atop UDP, which is also a perfectly acceptable and publicly available Internet protocol. And Chrome will happily use QUIC with non-Google hosts, the real problem is that production-quality QUIC server software is currently rare outside of Google.
- _wmd 9y agoOne of the major downsides to UDP is that it lacks any form of congestion control, so it's hard to justify QUIC's behaviour due to what it's built atop :) Meanwhile we're not talking about a small slice of bandwidth spent on SIP video calls playing unfairly, we're talking about 70% or more of all Internet traffic suddenly stampeding over every pre-existing protocol, they're the floodgates I'm worried about
- trevyn 9y agoIf this was actually a problem, it would be trivial for network operators to prioritize TCP packets over UDP packets. QUIC builds modern congestion control on top of UDP.
- solotronics 9y agoI think the problem is that currently there is no prioritizing within IP traffic and possibly this would cause TCP to suck while QUIC over UDP ran fine. This is just a guess based on how TCP congestion and sliding window work and I am very curious to see how these two interact at various percentages in the wild. If anyone knows how to simulate QUIC on Spirent or Ixia test gear please drop me a line and I will lab this up.
- fulafel 9y agoWe really don't want the prioritisation smarts in the network - End-to-end architecture of the internet, network neutrality and all that.
- IgorPartola 9y agoInternet traffic or web traffic? Last I saw, Netflix and streaming video were the biggest slices of the pie.
- vvanders 9y agoMy understanding is that most of that traffic is on the last mile due to them colocating the data at the ISP level[1]. [1] https://openconnect.netflix.com/en/ https://openconnect.netflix.com/en/
- gsich 9y agoWhy is TCP broken?
- pixl97 9y agoUse TCP on a lossy network. Keep adding more users till you are using a majority of the bandwidth. Watch the network fail in congestion collapse.
- glandium 9y agoUse TCP across continents. See how long it takes for the window size to ramp up until your bandwidth is fully used.
- wmf 9y agoDoes any other protocol do better? The Internet is not a truck.
- fulafel 9y agoAre you proposing a circuit-switched replacement for IP, or do you think the current network would serve better if there was no backoff in the face of congestion? The ATM effort was a while back, but who knows, maybe it's time to try again.
- apenwarr 9y agoThat's actually a misrepresentation. TCP actually works pretty well on crowded networks; a major feature of TCP is to avoid congestion collapse. It doesn't always fully saturate busy/lossy networks, which is an area for improvement, but it's not the same as congestion collapse. TCP BBR is an attempt to fix TCP congestion control so it can saturate busy/lossy networks more reliably. That doesn't require QUIC.
- fulafel 9y agoThis thinking is completely divorced from the principles and practice applied by the internet engineering community. The fairness benchmark is TCP, and if built on UDP, protocols are expected to respond to congestion & be fair to TCP streams.
- sebazzz 9y agoQUIC runs on UDP, does that mean it does not work on carrier grade NAT we see more and more these days?
- wmf 9y agoUDP works over virtually all NATs.