Being investigated
The problem appears to be very similar to the previous one - all routing on the link within BT was lost for just long enough to drop everyone off line, and they reconnected over the following minutes.
Note that lines on the wrong LNS are being cleared back to the right LNS with a short PPP restart now.
We need to get to the bottom of this with BT, obviously. We thought it may be related to some other work they were doing last week, but seems not now. We are also planning changes to the way the system reacts to issues like this to ensure they are much less disruptive.