{
  "id": 12159049,
  "title": "My bufferbloat test gave an A+ to a line it never loaded",
  "url": "https://urgent.news/2026/10/05/my-bufferbloat-test-gave-an-a-to-a-line-it-never-loaded",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-10-05T13:30:00.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/dtisch/my-bufferbloat-test-gave-an-a-to-a-line-it-never-loaded-2e21"
  },
  "original_language": "en",
  "account": "A recent network diagnostics app test incorrectly gave a perfect score (A+) to a sluggish connection that never transmitted any data. Bufferbloat, a phenomenon causing video calls to stutter due to router or provider backlog, is measured by comparing latency during idle and overloaded conditions. The test protocol involves loading and uploading data, then observing latency changes. Cloudflare's network encountered Russian throttling that prevented full data transmission. The test judged the connection as flawless despite no data moving, as it lacked a crucial condition: both download and upload needed to exceed 1 Mbps and 0.5 Mbps respectively within 10 seconds. Without this, the test deemed the load untested. NetDiag+ rectifies this by dismissing grades when data thresholds aren't met, attributing the verdict as \"cannotGrade.\" This highlights the importance of validating third-party responses before interpreting results.",
  "summary": "Some users of my network diagnostics app were getting an A+ bufferbloat grade on connections that, during the test, moved a few kilobits per second. The line was not perfect. The test had simply never loaded it. Here is how that happens, and the check that was missing. How a bufferbloat test works Bufferbloat is what makes a video call stutter while someone else in the house downloads a big file:…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}