I'm trying to figure out whether this is the same issue I am experiencing with my VB104W, we got connected finally on the 3rd of january after signing up on the day they released VDSL. Late november sometime.... That aside the speeds have been a vast improvement on ADSL2 with around 31Mbps down and 6 up to most NZ speedtest servers.
Our issue however is that sometimes twice a day, sometimes once every 3 days the internet light on the router will go red, it won't allow you to connect to it and the wireless connection shows as limited. When tested with windows diagnostics it says the DNS server isn't responding. I've tried using google's public DNS on my local settings instead of auto detecting from the router and this doesn't fix the issue. The problem is beginning to become more frequent as i have had to reset the router 4 times so far today, twice since disabling logging. I also reset it twice yesterday.
TL:DR - VB104W drops all connectivity, doesn't allow access to web portal. Internet light goes red and sometimes a power cycle fixes it, other times it takes 2 power cycles. Anyone experiencing similar issues? Apart from this speed seems good while it is running so i don't think i've been affected too much by the Dynamic Line Management during our first 2 weeks.