[littlestymaar]

> Browsing HN only needs one round-trip

It's never just one round-trip: the TCP handshake is one round-trip in itself, then there's the TLS handshake needing two addionnal round-trips, and only then comes the HTTP round trip. So the minimum latency you can have to load just the HTML is in fact 4 times the round-trip time. (And I left DNS aside, because the DNS resolution process involves talking to different servers that are thelselves at different distances).

[oefrha]

> It's never just one round-trip

That’s not true. TLS 1.3 0-RTT cuts down on handshake roundtrips, taking one roundtrip to establish the TCP connection before data can be sent; and HTTP/3 (QUIC) with 0-RTT actually makes it zero roundtrip, HTTP request is sent directly and response is received in one roundtrip.

[littlestymaar]

Thanks for pointing that out, it looks that my knowledge was a bit outdated.

It looks like the 0-RTT thing only work for connection resumption so it will only work if the user has already visited the site before.

Still, even without it, TIL that since TLS1.3, there's only a single round-trip and not two in the TLS handshake.