
Understand HTTP3 in 5 Minutes - ausjke
https://www.jesuisundev.com/en/understand-http3-in-5-minutes
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daenz
Reading about QUIC (the basis of HTTP3) a little more, it looks like it is
attempting to replace TCP entirely. It does this by making the reasonable
assumption that all connections should be secure (via TLS), and so it merges
layer 7 TLS protocol down and integrates it at the transport layer. It also
has its own flow-control and reliability mechanisms, like TCP. If QUIC "wins",
I don't see an obvious use for TCP.

~~~
avmich
TCP remains for cases where speed is required so TLS is skipped.

Instead of application layers, I'd assume evolution on transport layers, so
next to plaintext TCP there would be less reliable faster transport protocol,
secure but slower transport protocol and possibly others.

Similarly, is UDP a zero cost layer? If not, one could perhaps get more speed
from working directly with IP.

