Networking & Protocols
QUIC internals: free-recall review
Retrieval beats re-reading. For each prompt, say or write a full answer from memory before you open the model answer — the effort of recall is what makes the mechanism stick.
Reconstruct the unit’s spine — why QUIC lives in user space, how stream independence and Connection IDs work, what the 1-RTT and 0-RTT handshakes cost and save, and when to deploy QUIC versus TCP — without looking back at the lessons.
- 01Why does QUIC run its transport logic in user space over UDP, and what does that buy at what cost?
- 02Explain head-of-line blocking and how QUIC's stream model fixes it, with numbers.
- 03How does a QUIC connection survive a WiFi-to-cellular handoff, and what guards the migration against abuse?
- 04Why is QUIC's handshake 1 RTT instead of TCP+TLS's 2, and how do the four encryption levels and packet-number spaces fit in?
- 05What does 0-RTT resumption save, why is it replay-vulnerable, and how do you defend it?
- 06When should you deploy QUIC versus TCP, and what operational gaps does QUIC's encryption create?
If you could reconstruct each answer from memory, you hold the unit’s spine: user-space placement buys evolvability at a CPU cost; stream independence kills head-of-line blocking; Connection IDs survive migration behind path validation and a 3x anti-amplification guard; the merged 1-RTT handshake saves a round trip and 0-RTT saves another at the price of replay; and the deployment call is always CPU-versus-latency, with encryption forcing observability up to the application layer.