I'll start by saying that my brother has been having the same issue for longer(About 3 weeks) and just last night I started having them too. In addition to this, my ping in online games has been degrading consistently over the last week(From an average of 85-90 to 125-140).
What happens is a short 10-15 second disconnect from service(ethernet and wifi) which is enough to boot you from any online game.
The issue doesn't seem to have any sort of pattern. Some times I can stay connected for over a half hour, other times I will get disconnected 4 or 5 times in a 10 minute span.
If its happening on both WiFi and a hard wired ethernet connection then it sounds like one of 2 things. Your modem is faulty but more likely you have a losing sync issue. It's best to call technical support or use the live chat as they can run diagnostics on your line to see whats happening.