I’m trying to document an unreliable connection before contacting my ISP again. Their basic line check shows everything as normal, but during regular use pages stall, calls break up, and downloads briefly stop. I see the same behavior on a wired device after restarting the modem, so it does not match the stable service I expected.
Do others see this kind of mismatch between ISP tests and actual use, and what records helped demonstrate that the connection was bad?
Record whether the wired device is connected directly to the modem or still passes through your router. The ISP may blame local equipment unless you can show the problem occurs with one computer, Ethernet, Wi-Fi disabled, and the router temporarily removed from the path.
Run a continuous ping test for a few hours and save the output with timestamps. If possible, ping both your ISP’s first gateway and a reliable outside address. That helps separate a local line problem from a wider routing issue. Save each internet speed test result too, but packet loss and latency spikes usually explain stalls and broken calls better than download speed alone.
Keep a short log showing the exact time, what failed, and how long it lasted. Screenshots of modem signal levels and event logs can help as well. An ISP line check is often just a snapshot, so an intermittent connection can look normal during the test. A few days of timestamped evidence gives support a specific window to investigate instead of another generic “restart the modem” response.
A gateway that ignores ping packets while normal traffic passes is very different from a line that drops everything, so don’t rely too heavily on first-hop ping loss. Test two or three outside addresses at the same time and note whether all of them fail together. If they do, give support the exact outage times and ask them to check modem registration or signal history for those windows. That is harder to dismiss as a single server or ICMP issue.
You probably won’t get a single test that “proves” the ISP is at fault. What confused me at first was that restarting the modem can erase exactly the evidence support needs. Before rebooting, photograph the status pages showing uptime, corrected and uncorrected errors, disconnects, and signal levels. Then capture them again after a bad period so there is a visible change.
The direct Ethernet test mentioned above still matters, but leave that setup running long enough for the fault to happen. A clean ten-minute test does not say much about a connection that fails twice a day. While testing, avoid cloud backups, game updates, and other heavy traffic because the ISP can reasonably blame congestion inside your home.
When it fails, note whether the modem’s connection light changes and whether its local settings page still opens. If the modem page works but several outside services stop together, that is useful. If even the modem page becomes unreachable, the modem, cable, power supply, or Ethernet connection may be involved.
I would send support a small set of clear examples rather than hours of raw ping output: exact time, duration, wired setup, what stopped working, and the modem readings before and after. Ask them to check historical signal levels and disconnect records for those exact times. That gives them something specific to compare against instead of another snapshot taken while the line happens to be behaving.
Don’t reboot the modem right before you call in. That erases the error counters and uptime, which is usually the only hard evidence support can’t wave away. Grab those screenshots first, then reboot if you have to.