As I said before, 'It is always in the early hours of the morning'. Actually, to be more specific, it is ONLY in the early hours of the morning.
I have monitored SNRM and the latest log from a few days ago shows a max SNRM of 6.8 and a min of 5.3, but this is when there have been no dropouts. The max no. of CRCs per minute was 10 and that was only for one minute.
Whenever I run the monitor, the line has no problems - example of Murphy's Law.
'Noise being introduced on the line between you and the exchange.' - Possibly, but why is it only ever between 1am and 7am?
'Maintenance work at the exchange.' - Possibly. Do BT work overnight at exchanges?
'Does the line run past any light industrial areas?' - Possibly, but only in the early hours of the morning
My guess is maintenance work, but after 1 am?
This only occurs about once per month at a guess, but of course it causes re-syncs, which knocks my profile down a notch or two for several days due to BT's silly profiling system.
PS - what causes the upstream sync to vary such a lot when this is happening? It starts off at 448 and goes as low as 128.
Edited by rnewfie (Tue 26-Apr-11 13:26:41)