Called up AussieBroadband yesterday because the VDSL dropped in the middle of work again, and it's getting old. Tech support mentioned that I hadn't had any dropouts since March up until just this weekend - bullshit! They then suggested they try a port reset, but I didn't want to do that immediately as I was still working, so I was to call them back any time before midnight. I forgot all about it, and called them up right before bed at about 9pm.
That tech said that no, a port reset was no good - they use that when you have zero sync, I have sync. After discussing some options, trying out the other modem, running a line test, we stumbled upon something I didn't know... because my pfSense router handles DHCP, and it often doesn't start a new session when the sync drops and comes back, they have absolutely no way of telling that the line has been down. I was under the impression they had records of the dropouts from the node side, but apparently NBNco keep that information to themselves, only showing a ternary description of the line state: "stable", "unstable", and "no sync".
I'm told that the threshold between "stable" and "unstable" is ~2.6 sync drops in a 24 hour period, but if AussieBB can't spot them all that explains why the last time when I had three dropouts in a day and called them up, they weren't excited about helping... from their perspective the drops didn't exist!
So this morning before work I jumped on the DM200's configuration and swapped it over so that it handles DHCP. It's sub-optimal (I have double-NAT now, and probably things like the PS4 and the Switch aren't going to be super happy playing games) but it's not forever, and hopefully that lets them see the drop outs. Like the one that happened today at 1:48pm!
I'm going to have to start keeping a log of all these events until this is fixed, I think. :(