Downtime=BT 
Really, I don't understand why IDNet can't choose a more reliable backbone provider, or at least offer some more reliable business-quality connections like lower-contented SDSL or a LLU-based product.
SDSL is available (
Link),but I think it depends whether your exchange (and your wallet) will support it.
As for LLU... that would mean (afaik) IDNet putting their own kit into all the exchanges and their own backhaul, expensive.
Not sure about other backbone providers, but Enta do that and, judging by some comments in the forum, it has its own downsides