q-ecn
· RFC 9000 §13.4 · correctness · layer quic · udp/4468 · MUST
Passing this means: Rejected something invalid, with the code the RFC names.
Anomaly type: transport
How each client answered
| Client | Version | Verdict | What happened |
|---|---|---|---|
| curl | libcurl/8.23.0 ngtcp2/1.25.0 | Pass | Responded correctly: echoed ECN counts back in its ACKs: 7 ECT(0), 0 ECT(1), 0 ECN-CE. |
| quinn | noq fork (189b0ed) | Pass | Responded correctly: echoed ECN counts back in its ACKs: 13 ECT(0), 0 ECT(1), 0 ECN-CE. |
| aioquic | 1.3.0 (PyPI wheel) | Unsupported | does not report ECN counts. Another peer has echoed the markings this same port sent, so the codepoint demonstrably survives the path from here -- this client simply reported nothing, which §13.4.1 permits where the ECN field is not accessible to it. |
| chromium | build 1248 | Pass | Responded correctly: echoed ECN counts back in its ACKs: 12 ECT(0), 0 ECT(1), 0 ECN-CE. |
| quic-go | quic-go v0.61.0 (h1:9So2anK4Tp22) | Pass | Responded correctly: echoed ECN counts back in its ACKs: 18 ECT(0), 0 ECT(1), 0 ECN-CE. |
| quiche | 0.30.0 (1c8e976) | Unsupported | does not report ECN counts. Another peer has echoed the markings this same port sent, so the codepoint demonstrably survives the path from here -- this client simply reported nothing, which §13.4.1 permits where the ECN field is not accessible to it. |
| neqo | 0.31.1 (cac2b74) | Unsupported | does not report ECN counts. 4 of its own datagrams reached this endpoint carrying ECT, so the path preserves the codepoint in both directions and this client's stack sets it -- but nothing came back about the markings we sent, and §13.4.1 requires reporting only where the ECN field is accessible to the endpoint. |
| picoquic | 8162550 | Pass | Responded correctly: echoed ECN counts back in its ACKs: 7 ECT(0), 0 ECT(1), 0 ECN-CE. |
| ngtcp2 | 3c23148 | Pass | Responded correctly: echoed ECN counts back in its ACKs: 26 ECT(0), 0 ECT(1), 0 ECN-CE. |
| lsquic | 4.9.4 (2b30189) | Unsupported | does not report ECN counts. 6 of its own datagrams reached this endpoint carrying ECT, so the path preserves the codepoint in both directions and this client's stack sets it -- but nothing came back about the markings we sent, and §13.4.1 requires reporting only where the ECN field is accessible to the endpoint. |
| xquic | 2060a44 | Unsupported | does not report ECN counts. Another peer has echoed the markings this same port sent, so the codepoint demonstrably survives the path from here -- this client simply reported nothing, which §13.4.1 permits where the ECN field is not accessible to it. |
| msquic | 2.7.0 (7e6525d) | Pass | Responded correctly: echoed ECN counts back in its ACKs: 12 ECT(0), 0 ECT(1), 0 ECN-CE. |
| quico | 0.7.0 (npm) | Unsupported | does not report ECN counts. Another peer has echoed the markings this same port sent, so the codepoint demonstrably survives the path from here -- this client simply reported nothing, which §13.4.1 permits where the ECN field is not accessible to it. |
What the clause requires
Echo the ECN counts back in ACK frames carrying an ECN section (type 0x03). §13.4.1 makes this a conditional requirement — an endpoint MUST report the markings it receives "if these are accessible", and explicitly permits an endpoint with no access to the ECN field to report nothing. So counts coming back is a pass, and silence is never a failure. Silence is read against the path rather than left unresolved. Both directions cross the same path: a client whose own datagrams reach this endpoint still carrying ECT has shown the codepoint survives and that its stack sets it, and so has a port where any peer has ever echoed the markings sent from it. Either makes the silence the client's own and the result `unsupported` -- a property of the client, which §13.4.1 expressly allows. Only where nothing has shown the codepoint surviving is the run inconclusive, because only there is a stripped path still a live possibility.
Judged against RFC 9000.
Run this one yourself
Every test is reachable from your own client. Nothing here needs an account.
curl -s https://conformance.pqcrypta.com/catalog.json \
| jq '.tests[] | select(.id == "q-ecn")'