Cyber, since your problem is intermittent, a standard tracert likely will not work unless you get very lucky. I'd suggest a 3rd party tool (I suggested pingplotter previously, but anything that works similarly will work) to get usable data. As soon as you start lagging, go out and see what the tool says. You want to look for where the dropped packets or very high ping hops are. If the tool doesn't show anything usable, it is likely on your end.
Hopefully your ISP will actually help you out when you figure out where the issue is. Between 4 and 11 P.M. my ISP decides to send my traffic through CO to get to DC and effectively doubles to triples my latency. I called them and they told me "there is nothing we can do. We don't guarantee low ping or latency, only the total throughput." Fucking centurylink DSL jackoffs. Sadly there isn't anything else out here I could get. Hopefully I'll be moving soonish to a different part of FL and be able to get decent interwebs.
What: my life skills use meat
“Let us be thankful for the fools. But for them the rest of us could not succeed. ” -Mark Twain