Video calls kept stuttering, but every speed test said my connection was fine. When I contacted my ISP, the problem was often gone by the time anyone investigated. And I had no useful evidence to show their support team. Reading traceroutes and ping graphs isn't something most people want to do, so I built NetworkTests Monitor to keep watching the connection and explain what's going wrong in plain English. What it does It runs in the background on Windows, macOS, and Linux, and: Monitors your router, your ISP's first visible hop, and three independent internet endpoints every second. Identifies patterns that help distinguish Wi-Fi, router, ISP, VPN, and destination-specific problems. Measures call quality (packet loss and jitter) to the nearest test server. Lets you troubleshoot a website, app, or address by checking DNS, connection establishment, TLS certificates, server response, and network route. Recognizes VPN paths to help distinguish problems inside the tunnel from issues with your regular connection. Exports a PDF evidence report you can share with your ISP instead of just saying, "My internet is slow." On Linux, it can also run headless as a server, with the dashboard in your browser (people running homelabs and Raspberry Pis asked for this). How I built it Go for the monitoring engine, with one codebase across the supported platforms. Wails for the desktop application, with a plain JavaScript frontend. SQLite for local monitoring history. Four small test servers across the US West, US East, Europe, and India for speed tests and checking whether a service is down more broadly. There's no account or central dashboard. Monitoring history is stored locally on your computer. The app sends the network traffic required for monitoring and diagnostic tests, along with update checks. Things I learned along the way Linux can deliver ICMP error responses through a separate error queue for permission-free ping sockets. Miss that behavior, and hops can appear to have 100% packet loss when they don't. Some routers include only eight bytes of the original probe in their replies. My initial packet-matching logic silently discarded valid responses. Detecting VPNs by adapter name is unreliable. Looking at the OS's routing and adapter information proved more useful across the VPNs I've tested. Switching VPNs changes the network path, so comparing measurements against the old baseline can generate false alarms. The app now resets its baseline when the path changes. Where it stands It's free for personal use, doesn't require an account, and is closed-source. The Windows version is available through the Microsoft Store, with other platform builds available on the website. I'd genuinely appreciate feedback on two things: Can you understand what's wrong with your connection from the Overview screen in 10 seconds, without reading a manual? What would make a tool like this useful enough to keep running every day, rather than opening it only when something breaks? Project: https://networktests.com/monitor I'm the developer, so I'm happy to answer technical questions or explain how any of the diagnostics work.   submitted by   /u/hostanywhere [link]   [comments]