In reply to a post by JayCee9:

Is it possible the Asus has caused the speed fault?...I was unplugging/plugging back in the DSL line from the BT Faceplate quite a few times.

I have neither, but I've seen a lot of problems on here with both the HH5 and the Asus VDSL2-products that I'd trust neither to act as a stable platform wrt DLM.

The problems that cause me to have no trust in them can be fixed, I'm sure - and there are others who will be paying more attention to the exact current status, who can tell you more. I have them in my head as "avoid like the plague", and am currently using a Billion 8800NL.

The act of plugging & unplugging can have a detrimental affect whatever modem you use. In the early days, it had seemed considerably better than ADSL2+ (ie was less sensitive), but the current best practice is to turn modem power off before unplugging the line, and leaving it off for at least half an hour. That ensures DLM sees at least one complete 15 minute period with no sync attempts.

Can it have caused the DLM to have kicked in?
And if it did would DLM on it's own almost halve the normally attained speed?

DLM can kick in at any time, for non-obvious reasons, at the best of times. It can certainly have dramatic effects if things have been really going wrong - especially if the modem keeps resetting or resyncing due to a fault.

And the Asus seems to suffer precisely this problem...

http://www.broadbandbuyer.co.uk/products/19269-asus-...

As does, unfortunately, the HH5.

We have investigated this with Asus.

It would appear that they have added us into their SP listings, based on one of our customers contacting them.

We have however asked for a copy of the settings Asus are supplying to make sure they do indeed match our requirements.

In reply to a post by MHC:

Yes, you should be getting around 58Mbps - or could.

I wonder if the 35-38 you were seeing was because the line was capped at 40Mbps - which gives a max throughput of 38. Certainly 16-18 is way off. See what happens when it is fixed.#

After a visit from an Openreach engineer on Friday I'm now getting 60Mbps downstream...Woo-Hoo
This was a 3rd visit by an engineer, on the previous 2 visits they made a phone call to get my line reset and the speed increased to around 30Mbps but the HH5 was still dropping the connection every day and the speed was intermittently dropping. Luckily every visit was followed up the next day by a phone call from BT so I was able to tell them it still wasn't fixed.
On Friday an engineer visited again and plugged his handheld terminal into the BT faceplate and the speed indicated was around 12Mbps and he said it should be much better than that, further tests on his terminal showed a fault 25 metres along the line which is roughly where the BT Pole on our back road is so he got his ladder and climbed the pole. He was up there around 30 mins and I noticed the HH5 was back online so I ran a speedtest and was astounded to this this hovering around 59Mbps...when he came into the house he said he'd found 2 twisted pairs inside the box where the connections had been transposed by a previous engineer and also a brittle and kinked connection which he replaced.
This is the sort of speed I should have been getting from day one, however, all's well that end's well. He also replaced the HH5 to be on the safe side and so far it's been stable and holding up at around 58Mbps-60Mbps since.