4 ms·

I have seen SO MANY "reliable UDP" transports written instead of TCP over the decades. Off the top of my head: TIBCO, SaltStack, various games have bespoke UDP

I have seen SO MANY "reliable UDP" transports written instead of TCP over the decades. Off the top of my head: TIBCO, SaltStack, various games have bespoke UDP / TCP hybrids IIRC. Is TCP really that fundamentally slow? How could high-level repurposes of UDP be faster than presumably hardware optimized and heavily analyzed TCP stacks? The lies, damn lies, benchmarks seems a bit applicable too here. He's disabling caching? Really it is testing a specific transport situation, but caching IMO would mitigate a lot of the dramatic advantages? And what about cloudflare edge caching outside the browser? I think he was routing all resource requests through his single server that probably isn't cached properly. So with good caching will HTTP/3 produce the advantage for the everyman over HTTP/1.1 to justify the attention?

Dylan16807 5y ago
You can't control TCP very well, and you can't do anything about head-of-line blocking. So yes, for lots of circumstances it's easy to beat TCP. Importantly, a custom protocol over UDP can do things that are incompatible with 30 year old TCP implementations. And you don't need hardware optimization until you're getting into many gigabits per second.