SDG Connection Test

A small, auditable diagnostic for proving or disproving whether a specific ISP is blocking or throttling the UDP traffic that Space Engineers, Torch, and Steam depend on.

How to run it

1. Install Node.js 20 or later (LTS is fine).
2. Download the release zip above and unzip it.
3. Open a terminal (PowerShell, cmd, or bash) in the unzipped folder.
4. Run, substituting the host SDG gave you:

   node client/client.js --host <server-given-by-SDG>

5. Review the “what this will do” summary, press y, wait ~90 seconds.
6. If SDG asked for a JSON report, re-run with --json report.json and send the file back.

What it does

The client probes every TCP and UDP port that Space Engineers, Torch, and Steam actually use, measures reachability / loss / latency / MTU on each, and runs a 10-second sustained UDP traffic test that mimics real game traffic. Results print to the console and, on request, to a JSON file.

It does not read your files, environment variables, browsing history, Steam install, or anything else off your machine. It only sends the test packets to the host you pass on the command line.

Why you can trust it

The client is a single ~500-line JavaScript file with zero runtime dependencies and is deliberately written to be skimmable in ten minutes. Three layers of audit:

• Read the source — client/client.js on GitHub. The transparency notes walk through what to grep for and what each match means.
• Watch the packets — run with Wireshark capturing on your active NIC. Every outbound packet has the same 8-byte session nonce printed at startup, so you can filter by it. Every packet matches one of the layouts in the protocol spec.
• Run it in a sandbox — Windows Sandbox, a throwaway VM, or a Docker node:20-alpine container all work.

What the server logs

The operator-deployed server records minimal session metadata for diagnostic correlation: source IP, source ASN/ISP, a client-generated nonce (printed at client startup so you can correlate captures), per-port packet counts, and rate-limit counters. Logs are capped at ~100 MB total on disk, never shipped off-host, and never correlated with Steam or in-game identity. Full detail in the privacy notice.

Source & license

MIT-licensed. The client and shared protocol code live at github.com/sdg-net/sdg-connection-test. The server implementation is operator-internal; the security model and behavioral guarantees are spelled out in SECURITY.md.

Built by SDG. Hosted at sdg.knowledgeondemand.net. Source: github.com/sdg-net/sdg-connection-test.