For more than a year I’ve been reporting that around 10pm every night our Comcast internet becomes unusable. Streaming video fails, web pages start timing out. Media content in Facebook and Twitter stop loading. Every time I have looked, the problem is the same: the Sunnyvale node is dropping packets. Like this:
Over the course of the year, I have sent them pings, traces & speed tests over my network. From neighbors who all report the same thing, and even over a modem they installed in parallel with mine here (when they were claiming it was my modem in Alameda causing the packet loss in Sunnyvale!). It is always the same. Around 10pm the network becomes intermittently unusable, and it is always the Sunnyvale node that is dropping packets. It will stay bad until after midnight most nights.
I’ve been told that the router dropping ICMP is normal (not true: it is true that it will drop ICMP packets first when overloaded though, so the high loss rate indicates an overloaded router; the failing video & web downloads tell me it is dropping other packets too).
I’ve been told it must be my router, my modem or the cable into the house. Nobody has been able to explain how any of those things could result in packet loss at Sunnyvale though.
When the network is working, Speedtest results look like this:
Just after 10pm that periodically changes to this:
Every time I report it we go through the same sequence. First there is the request to send a tech to my house to check the wiring (total waste of everybody’s time since it is obvious the problem is in Sunnyvale, about 45 miles from here), then the request to send the logs (I’ve been sending them for months). Then radio silence. Until I ask again, when they repeat the process.
At no point do they ever get the networking team to admit their network is becoming overloaded. A year after I first reported it, their network is apparently still unable to cope with the traffic passing over it between 10pm & midnight. Not continuously though. It is intermittent. Randomly, there will be a few minutes where nothing works, then it will be back. Streaming video fails, web loads timeout. My neighbors tell me they get dropped from conference calls too, making it hard to do late night calls with overseas teams.
I am starting to wonder whether Comcast actually knows how to run an IP network. It certainly seems that every time I contact them they try to find a fault in the cable TV related parts of the system. Never in the IP network. I can’t believe they don’t have load charts for that node. Or statistics on packet drop rates. I just suspect they aren’t even looking.