{"abstract":"Retransmitted segments do not supply ambiguous rtt samples.","category":"Transport flow control","checks":4,"contract":"Bounded offline decision model: retransmitted segments do not supply ambiguous rtt samples. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","contract_signature":"retransmitted, sample","evaluation_group":"xh-retransmitted-segments-do-not-supply-ambiguous-rtt-samples","failed_approach":"The attempted repair uses `None` and still violates a separate fixture.","family":"xh-retransmitted-segments-do-not-supply-ambiguous-rtt-samples","id":"FA-7251","implementations":{"attempt":{"sha256":"59aaaa5152f50633d05908bdbc29c105fdfa3ca65ca9d629de123d72091aa318","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(retransmitted, sample):\n    return None\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(True, 10), None)\", \"check('fixture 2', solve(False, 10), 10)\", \"check('fixture 3', solve(False, 0), 0)\", \"check('fixture 4', solve(True, 0), None)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"9284af5d5f5be49d27ee2a0dc400de130d072b96740369ff554be9d3e3708169","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(retransmitted, sample):\n    return sample\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(True, 10), None)\", \"check('fixture 2', solve(False, 10), 10)\", \"check('fixture 3', solve(False, 0), 0)\", \"check('fixture 4', solve(True, 0), None)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Bounded deterministic policy model over validated inputs; not a complete protocol stack or an interoperability claim. The five variants rotate the same explicit fixture set. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"xh-retransmitted-segments-do-not-supply-ambiguous-rtt-samples","generated_at":"2026-09-29T14:38:09.835179+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic transport flow control model isolates the retransmitted-segments-do-not-supply-ambiguous-rtt-samples policy at a network component boundary.","root_cause":"The faulty implementation uses `sample` for the retransmitted-segments-do-not-supply-ambiguous-rtt-samples decision.","sha256":"bdab58fc6448eaa8f53f75ea6e20621635e37d9be4f8937f5ea1014c597feb93","title":"Retransmitted segments do not supply ambiguous rtt samples · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":48.397,"exit_code":1,"observations":[{"actual":null,"check":"fixture 2","expected":10,"passed":false},{"actual":null,"check":"fixture 3","expected":0,"passed":false},{"actual":null,"check":"fixture 4","expected":null,"passed":true},{"actual":null,"check":"fixture 1","expected":null,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": null, \"expected\": 10, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": null, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": null, \"expected\": null, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":48.7,"exit_code":1,"observations":[{"actual":10,"check":"fixture 2","expected":10,"passed":true},{"actual":0,"check":"fixture 3","expected":0,"passed":true},{"actual":0,"check":"fixture 4","expected":null,"passed":false},{"actual":10,"check":"fixture 1","expected":null,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 10, \"expected\": 10, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 0, \"expected\": null, \"passed\": false}, {\"check\": \"fixture 1\", \"actual\": 10, \"expected\": null, \"passed\": false}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}