Same problem here. There seems to be no connection between ISPs or where you live.
I’m on Comcast in MI, USA
Seems whenever I have lag issues and DC in GW2 (keeps happening around every 5 minutes) the rest of my net lags out too. But when I don’t touch the game I have no problems.
So I assume its an issue with a lot of ISPs with something that changed in GW2, forcing a negative outcome from your connection as a whole. Really weird, but nothing we can do about it until arenanet undoes whatever they changed.