For the past eight days, my internet connection has been extremely unreliable. Web pages often sit loading indefinitely, even after I reset the equipment, tried another router, replaced the Ethernet cable, and had the provider install a new ONT.
The engineer claimed the router's cable was not capable of handling my connection because it supposedly supported only around 500 Mbps, and suggested buying a Cat 6 cable rated for 10 Gbps. That explanation seems questionable because speed tests on several devices have reached roughly 1.2 Gbps.
A continuous ping test shows normal latency around 12–20 ms at times, but it also spikes into the thousands of milliseconds, reaching more than 20,000 ms. The connection is being tested mainly over Wi-Fi, although I can also test directly over Ethernet.
What should a healthy ping graph look like, how much variation is normal, and what could cause latency spikes this severe?
4 Answers
A cable can be damaged or poorly terminated, but its advertised speed is not what causes random multi-second latency spikes. A cable that cannot negotiate the required speed would normally produce a slower link, errors, or disconnects—not briefly turn a 20 ms connection into 20,000 ms. It is still worth trying a known-good cable, but the provider’s explanation sounds incomplete.
The pattern could also be bufferbloat or congestion. When the connection is busy uploading or downloading, packets can sit in a queue and latency rises dramatically even though a speed test still reports high throughput. Run the test while the network is otherwise idle and again during a large upload or download. If it only happens under load, the router may need smart queue management, or the provider may need to investigate congestion.
Test this with a computer connected directly to the router by Ethernet, then run separate pings to the router and to a reliable internet address. If the ping to the router spikes, the problem is local Wi-Fi or router-related. If the router stays responsive but the internet ping spikes, the issue is farther upstream with the provider or network congestion.
Wi-Fi can introduce interference and unstable latency, especially on a crowded channel, but spikes measured in seconds are much worse than normal Wi-Fi variation. Try both frequency bands, change channels if possible, and compare several devices in the same location. Ethernet is the important control test.
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