My internet kept dropping at 11 PM every night. Not slowing down — dropping completely. I called the ISP twice, paid for a technician visit that resolved nothing, and finally decided to figure it out myself. What followed was three weeks of systematic testing, some embarrassing mistakes, and a genuinely useful education in network behavior.
Setting Up the Experiment
The first thing I did was stop guessing and start logging. I used a free tool called PingPlotter to record latency and packet loss every 30 seconds over 72 hours. Within two days, the pattern was obvious: packet loss spiked consistently between 10:45 PM and 11:30 PM, always at the second hop — meaning the problem was not inside my house, but on the line between my router and the ISP node.
That single piece of data changed everything. Without it, I was checking my own equipment for hours.
What the Logs Actually Revealed
Once I had timestamped evidence, I cross-referenced it with my neighbor's usage patterns. Turns out three apartments in our building shared a coaxial segment, and two of them were streaming in 4K during the same window. Signal-to-noise ratio on the shared line dropped below acceptable thresholds under that combined load.
I confirmed this by running a cable modem diagnostic page — most modems expose this at 192.168.100.1 — and checking the downstream SNR value. Anything below 30 dB is a warning sign. Mine was hitting 23 dB during peak hours. That is not a router problem. That is an infrastructure problem.
The Lessons That Saved Real Money
Key findings from the three-week test
| Problem Identified | Tool Used | Cost of Fix |
|---|---|---|
| Packet loss at ISP hop | PingPlotter (free) | $0 — ISP replaced the node splitter |
| DNS latency spikes | namebench (free) | $0 — switched to Cloudflare DNS |
| Router overheating | Physical inspection | $0 — moved router off shelf |
| Old coaxial splitter | Signal meter app | $8 — replaced splitter myself |
Total spent: $8 and roughly 15 hours of my time. The ISP visit alone had cost me $60 and solved nothing. The difference was having documented evidence instead of vague complaints. When I called the ISP the third time with timestamped PingPlotter graphs and modem SNR screenshots, they escalated the ticket within hours.
One Thing I Would Do Differently
Start with the modem diagnostic page before touching anything else. It takes four minutes and immediately tells you whether the problem is inside your network or outside it. That single check would have saved me about eight hours of pointless router resets and cable swapping.
Network troubleshooting is not glamorous work, but it is learnable. And when you can show an ISP exactly where their network is failing, the conversation changes completely.