What is QUIC?
QUIC is a transport protocol over UDP with reliable streams, connection management and encryption. HTTP/3 uses it but is distinct from it.
How it works and where it is used
1. How it works It numbers packets, detects loss and controls flow and congestion. Streams can progress independently; TLS 1.3 is integrated into connection establishment. 2. Applications and examples QUIC underlies HTTP/3 and can carry other application protocols. Connection identifiers may help across address changes, without guaranteeing seamless migration.
Limits and good practice
3. Limitations and security UDP restrictions, equipment policies and processing cost complicate deployment. Encryption changes what network observers can see. 4. Practical considerations Test loss, migration, timeouts and fallback. Follow current RFCs and maintained libraries rather than writing custom cryptography.