I'd like to hear from people who are getting VDSL2 through BT's FTTC offering (whether with BT or some other ISP). How common are PPP disconnections for you? The output of pppd on my Linux box (being used as my router, directly connected to the Openreach VDSL modem) shows that I am getting somewhat regular, though intermittent disconnections.
Sometimes the connection will stay up for 2 weeks, some days it will disconnect and reconnect 4 or 5 times. I have been told by Zen customer support that generally this is considered "stable" for VDSL2 because it is an unreliable technology and there's no 100% uptime guarantee. Whilst I understand this, it does seem like a very high level of unreliability considering I had literally months on end with no downtime back when I had ADSL2+ from Be, supposedly one of the less reliable ISPs. These disconnections aren't "invisible" either; for the 30 or so seconds that the disconnection/reconnection occurs, I lose the internet connection; no ping responses, IRC and other protocols requiring a constant connection drop out, etc.
Obviously I'm supposing this is a problem between my modem and the exchange, and not with my ISP, but it still seems bad; my line sounds fine on a quiet line test so why the regular disconnections? I've tried plugging the modem into a filter connected directly to the test socket too, to eliminate the internal wiring as a problem; the disconnections still occurred. I'd appreciate it if people could reply with their experiences; uptime/performance graphs would be good too.