Internet Becomes Extremely Slow After a Few Minutes—What Could Be Causing the Latency?
Asked by
MellowCedar47
My internet connection becomes extremely slow shortly after restarting my laptop and router. Rebooting both restores normal performance briefly, but the connection quickly degrades again.
I checked Windows Update and confirmed that nothing is downloading, and I also looked for other background programs using the connection. The problem happens in both Firefox with extensions and Chrome without extensions. I tested with Wireshark and TCPView, but I am not experienced enough to interpret them yet.
During the slowdown, pinging 8.8.8.8 produced response times between 624 and 1,419 ms, averaging about 1,052 ms, with no packet loss. The first hop to my router stayed around 2–3 ms, while the next several hops through my ISP increased dramatically. Two traceroutes showed the same pattern, although one run was much worse than the other. I use an Orange/Sosh connection and currently have 1.1.1.1 configured as my DNS server. What should I test next, and does this point to a problem with my computer, router, or ISP?
Answers
The missing router and service details would be useful, including whether the connection is fiber, cable, or mobile broadband and what speeds you normally receive. Check the router's status page for signal levels, synchronization errors, or WAN reconnects. If every device has the same problem, it is probably the line or ISP rather than Windows. If only this laptop is affected, then check its network adapter driver, power-saving settings, and whether another process is uploading heavily.
Reply to this answer
Before calling the ISP, run a few separate tests during the slowdown: continuously ping your router, your ISP gateway if known, and 8.8.8.8. If the router ping stays low while the external pings become huge, the issue is upstream of your home network. Also test with an Ethernet cable if possible, and try another device. A traceroute hop showing timeouts by itself is not necessarily a fault because routers often deprioritize traceroute packets, but the high latency continuing through to the destination is meaningful.
Reply to this answer
The traceroute and ping results suggest a serious latency problem somewhere beyond your home router. Since the first hop remains at 2–3 ms but the delay appears immediately at the ISP's next hop, your laptop and local Wi-Fi/router are less likely to be the main cause. Also, because you are pinging an IP address directly, changing DNS servers will not fix this particular symptom. Contact Orange/Sosh and provide them with the ping and traceroute results while the problem is happening; they may need to investigate congestion or a fault on the access line.
BrightNettle6: That makes sense. I was unsure whether the DNS setting could still be involved, but the high latency to 8.8.8.8 seems to rule out DNS lookup delays.
Reply to this answer
Add your answer
Answers are reviewed before publication.
MellowCedar47: I will test another device and use Ethernet during the next slowdown so I can compare the local router latency with the ISP route.