Zen Downtime in our case was approx 8 hours (2 X Business FTTC)
Almost 8 hours downtime for us. Zen did tweet to say that it wasn't BT, but were very scant on the details of their 3rd party supplier. We've been with Zen for over 10 years and they are generally very - very good - however this time their feedback to clients was poor IMHO. I will be expecting a full and frank post mortem on this major outage (210 exchanges in the list) and what steps will be put in place to mitigate the risk on-going. The only upside to this is (by luck as the incident kicked off at 15:50) that we lost only 90 minutes of core business time, however some of our out of office hours processes were affected. My personal Sky LLU connection on the same exchange stayed up through-out.
Zen Business Customer.