I have that issue from time to time, though usually it's on my end due to snowstorms.
If you see your packets drop, there's a good chance you might DC. Though I'm sure you've noticed that already. Packets are pretty much your latency, and connection to the server. Not much can really be done about it, as lag is something that's been an issue since beta. The Montreal (Last I checked, this is where all the NA/EU servers were located) servers have been a pain, and they really don't seem to be trying to fix things all that much... and if they are, it hasn't been very noticeable by those affected.

Either way, I would suggest WTFast. It helps with lag quite a bit. It gives a monthly free trial, and then asks for a sub. But as far as I've noticed, you should be able to just reinstall and get a new free month. Dunno if they've changed it or not, as I haven't used it in a few months. If it doesn't help, then not sure what to do :<

Good luck, and hope it helps.