I've been getting constant disconnecting/reconnecting for a couple of months now. It's a wired connection and the modems online light stays lit during the outages. The disconnects occur regardless of usage as I can see from Mumble logs throughout the night when no one's using the internet. Sometimes a couple of days will pass with no problem but they always return. It's made playing anything near impossible with the disconnects and packet loss/choke.
My problems seem to mirror this problem from November of last year, same modem and all: