Implementation

Telecommunications

Computer science

Control flow

Distributed computing

Computer network

Multiplexing

Software engineering

Programming language

The QUIC and HTTP/3 protocols are quickly maturing together with their implementations, though many of their low-level behaviours are not yet well-understood. To help improve this, we empirically compare 15 IETF QUIC+HTTP/3 implementations for advanced features like Flow and Congestion Control, 0-RTT, Multiplexing, and Packetization. We find a large heterogeneity between stacks, discuss uncovered bugs and conclude that most implementations are not fully optimized or validated yet. We argue that future work must prioritize rigorous root-cause analysis of observed behaviours, and show this is possible by employing our qlog and qvis tools.

Same Standards, Different Decisions