Which problem does HTTP/3 (over QUIC) fix that HTTP/2 still has?

Options

• ✗ Only one request at a time per connection
• ✗ No compression of headers
• ✓ One lost packet stalls every stream on the connection (TCP head-of-line blocking) Correct
• ✗ Traffic is not encrypted by default

Why

HTTP/2 multiplexes many streams over one TCP connection, but TCP delivers bytes in order, so a lost packet blocks all of them until it is resent. QUIC runs over UDP with independent streams. HTTP/1.1 had the one-request limit, and HTTP/2 already compresses headers.

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