Toby
77 lines
4.7 KiB
Markdown
77 lines
4.7 KiB
Markdown
# Cable Latency Survey
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Measurements, code and data behind four sites:
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| Site | Contents | Source |
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| https://pingstats.aethercosmology.com | Measured round-trip times between cities, compared with the minimum propagation time along submarine-cable routes on a sphere, a North-pole azimuthal equidistant (AE) map, an AE map centred on 0°N 0°E ("dual-pole") and a flat Mercator map | `src/` |
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| https://fe-map.aethercosmology.com | The best layout of 219 cities on a plane that a solver can find from timed flights, pings, rail and road lengths and satellite passes, and the same solve released into 3D | `femap/` |
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| https://iss.aethercosmology.com | The Sync Test: the ISS at its published-orbit position on the globe and three flat maps, with a spoofed radio signal moving at the speed measured by SatNOGS stations | `satellites/` |
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| https://distance.aethercosmology.com | The Shape of Distance: flights, triangles and satellite recordings | `src/handoff/The_Shape_of_Distance_PRESENTATION.html` |
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- Code: MIT (`LICENSE`). Measurements and derived data: CC BY 4.0, with third-party terms (`LICENSE-DATA.md`).
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- Corrections, new measurements and re-analyses: `CONTRIBUTING.md`. Issues and pull requests: https://git.aethercosmology.com/toby/cable-latency-survey.
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## Files
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| Path | Contents |
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| `cable_latency_survey_data_v2.json` | **Current data hand-off.** 29,341 measurements, 305 sites, every routed path and cable geometry (`[lon, lat]`). The `revision` block lists the changes from v1. |
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| `cable_latency_survey_data.json` | v1: the same measurements without coordinates. Kept for reference. |
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| `cable_latency_survey_report.html` | The report, identical to the website. |
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| `src/` | Pipeline code, raw logs and derived data (below). |
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| `femap/` | fe-map: solver (`fit.py`), build (`build.py`, `template.html`), result (`data/femap.json`), page (`site/`). |
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| `satellites/` | iss: build (`build.py`, `template.html`), orbital elements and SatNOGS timings (`data/`), page (`site/`). |
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| `src/handoff/The_Shape_of_Distance_PRESENTATION.html` | The Shape of Distance as published; the flights, limits and triangles used by `femap/` and the SatNOGS timings used by `satellites/` are read from it. |
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| `tests/` | Headless-browser checks of the sites (`tests/run.sh`). |
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### Raw measurements
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| Source | File |
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| Globalping probes, runs 1 and 2 | `src/data/live_20261023T1812Z.json`, `src/data/live_run2.json` (each result with its Globalping measurement ID) |
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| Vultr servers (8, 2026-10-23 21:23–22:30 UTC) | `src/data/vps/<server>/ping.log`, `src/data/vps/<server>/mtr.log` (traceroutes) |
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| Residential connection, Michigan | `src/data/home/ping.log` (location withheld) |
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| RIPE Atlas sea crossings | `src/data/trace.json` (hops, timings, measurement and probe IDs) |
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| WonderNetwork, 2020-07-19/20 | per-pair statistics `src/data/wn_clean.json`; archive downloaded by `src/fetch_raw.sh` |
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## Pipeline
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Run from `src/`. The measurement steps contact external services and are not
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needed to rebuild the report.
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| Step | Script | Output |
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| Distance on each model, constants | `models.py` | — |
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| Globalping measurements | `measure.py` | `data/live_*.json` |
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| Vultr servers: create, measure, collect, delete | `vps.py` | `data/vps/` |
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| Vultr logs to measurements | `vps_analyze.py` | `data/vps_cells.json` |
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| WonderNetwork archive: statistics, mislocated servers | `analyze_wn.py` | `data/wn_clean.json` |
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| Published cable lengths on each model | `cables.py` | `data/cables.json` |
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| RIPE Atlas sea crossings | `trace.py` | `data/trace.json` |
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| Cable-and-land routing on each model | `network.py` | `data/network.json` |
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| Best attainable flat arrangements | `flatfit.py` | `data/flatfit.json` |
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| Network attribution from public BGP data | `asmap.py` | `data/asmap.json`, `data/rpki.json` |
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| Shape fit without positions | `pingmap.py` | `data/pingmap.json` |
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| North-pole AE longitude solver (hand-off only) | `solver.py` | `data/solver.json` |
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| Report | `build.py` | `site/index.html`, `web/index.html` |
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| Data hand-off | `export.py` | `handoff/cable_latency_survey_data_v2.json` |
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## Reproduce
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```bash
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git clone https://git.aethercosmology.com/toby/cable-latency-survey.git
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cd cable-latency-survey/src
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pip install -r requirements.txt
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./fetch_raw.sh # TeleGeography, WonderNetwork and BGP inputs (not redistributed)
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python3 build.py # the report, from the files in data/
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python3 flatfit.py # flat arrangements
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python3 export.py # the data hand-off
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```
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`build.py` needs only `data/` and the TeleGeography files; it does not contact
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any measurement service. `fetch_raw.sh` reports whether the TeleGeography data
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it downloads matches the snapshot used (`src/raw/tg.sha256`).
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Browser checks: `cd tests && npm install && CH=/path/to/chromium ./run.sh`.
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