As I was getting disconnected once again tonight as soon one large raid came to defend our keep that was under assault by a large raid, I was (as always) unable to connect back for 5-10 minutes, being told each time to "check your Internet connection" when trying to log my character back into Cyrodiil, indicating that either the route is no longer letting me reach the actual zone server, or the zone server itself is refusing connections (note that the username/password login DOES succeed, the issue is only when trying to log the character back into the zone).
Is it possible that these disconnects + being unable to connect back for an extended period of time are caused by some DoS/flood protection within ZOS's network? It almost always happens when you are near a keep that is under assault by a very large number of players, meaning there's probably a lot of network traffic occuring in bursts. Is this something ZOS has actually investigated in all these years they've been trying (and failing) to address the major performance issues that mostly occur during very large scale battles in Cyrodiil?
Just some thoughts from someone who actually works in IT, and whose work involves server management and networking.