DLM

Is DLM smart enough to know it’s a time switch cutting of power to the Router at midnight for 6 hours each night – and not a ‘line’ fault?

Normally yes. It will only intervene when there are several in a short period.

Why is it being turned off? The cost saving could be as little, or less than 1p per day.

In reply to a post by rombic:

Is DLM smart enough to know it’s a time switch cutting of power to the Router at midnight for 6 hours each night – and not a ‘line’ fault?

It's not smart enough to know if you powered the modem off, if the power was cut or if the line was pulled out the wall.

It doesn't take any notice of the "dying gasp" (a message a modem sends to the DSLAM to say "this was a manual power off").
It treats them all the same.

However...

DLM doesn't count the number of times a line loses sync, or the number of times a line establishes sync.
It counts the number of times a line resyncs, only when there was activity detected on the line in the previous full time bin (a bin is 15 minutes).

So if your line is powered off for 30+ mins then the DLM doesn't count the line syncing back up as a retrain.

You're allowed numerous retrains a day anyway so you shouldn't be worrying about powering off the modem once a day.

Personally I wouldn't power off a router using a time switch - electrics take the most stress when they are powered on. It is quite possible any saving in power would be negated by the need to replace the router more often due to the stress on the circuits at power up.

Many thanks for all the replies. The problem relates to the power source in an industrial building controlled by this time switch and unfortunately there’s no convenient alternative.
The ISP concerned insists the reduction in line speed is a result of DLM kicking in so I did a similar test at home but it was inconclusive.

The ISP obviously does not know their **** from their elbow!

As mentioned in the other replies - one off and on per day will have ZERO effect. Several over a 15 minute period may well do, but as it is a straight OFF/ON then it is just one.

There is a localised issue here meaning my line drops once or twice a day and has been for the past couple of months. It resyncs maybe 12-15 Mbps lower with an SNR of 3 dB then as things resolve, the SNR goes up to 8 and achievable back to normal. I then do a reboot and get back to my normal 74 Mbps at 3dB. And that is day after day - up to four cycles and no changes.

Here is my BQM showing several in one day - and no significant change in attainable or sync.
My Broadband Ping