Target SNRM Reduction

[#1]

Hi,
Has anyone got any tips on how to have my BT target SNRM reset to a lower value?
When my line was in its training period, there was a fault that required me to plug in at the engineers socket, try different filters and routers etc, and I now wonder if all that connect/disconnect resulted in my target SNRM being set at a high 15. It stayed solidly at 15 for almost a year, until I suddenly had an unexplained huge sync loss (from 1300 down to 800). Testing was done, and the offered solution was to reset my target SNRM down to 12 - and it did the trick - sync back to 1250'ish (and low errors/no dropouts)......and it has stayed at 12 ever since.
I was motivated to rewire all cabling from the master socket outwards, cut the bell wire, and get expensive microfilters. That seemed to improve things, and I embarked on a program of looking for the most suitable modem. I found that I could get stable sync rates of 1500+, with no dropouts and low error rates at a (starting) SNRM of 7'ish, which would then decay to 6.0/6.25 at the worst time of day, using a DG834G V4 with SNRM-tweaking enabled. 
Having satisfied myself that my setup would cope with that SNRM of 6-7, I asked for Plusnet to reduce my target down to 9 - but my request hasn't been successful - I've been advised that if my line is good enough then the target SNRM should reset itself in due course.....does that seem likely?
Do you think it likely that I can persuade Plusnet to have my SNRM reduced to 9; are there any keywords/phrases that might do the trick?
Jack

[#2]

I presume you raised a ticket for the request - that's probably a canned response. Yes it will be automatically lowered by the DLM in due course but that may take some considerable time, weeks and weeks and weeks with your modem/router on continuously - not something all users will want to do.
Did you post all the information in your post above in the ticket? If not, post the ticket number here, post the information in the ticket, and add that you have approached things in a methodical manner to achieve the best from your line and see no reason to have to 'wait for the sytem' under the circumstances. A request to lower the target to 9dB is not unreasonable. Hopefully if this doesn't progress, one of the Comms team may pick it up.

[#3]

Thanks for the tips, Anotherone; I've recapped that info into the ticket ( 28562399 ) and re-requested.
Cheers,
Jack

[#4]

Another tip for you, as I can't remember if it was mentioned in your other thread, but when you go to do router swaps, filter swaps etc., powerdown your router first, and wait (the longer you can the better) several minutes at least before disconnecting the line. I would tend to avoid doing this more than about 5 times in an hour and then not for the rest of the day, otherwise DLM may think you have a problem and keep the Target SNRM where it is or at worst raise it. Good luck.

[#5]

Ah, I haven't been doing that wait-for-minutes, but will do FNO; probably the only time I exceeded that 5/hour rate was when I was trying out filters - I gave them 10 minutes each, then counted the various error rates.....but the results were suspect because the SNRM and sync rate usually altered at each re-connection. I then moved on to trying the apparent best for a few days each, and selected the best on that basis.
For the whole of last year, I rebooted the router once a week, and as I've now found out, not at the best day/time - for me, the best is Monday at around 8 am, alternatively 8 am any day except the weekend. So according to whats been said about the DLM, my target SNRM would never had chance to re-set.

[#6]

Obviously, the best time to do comparisons is when noise levels are nice and stable, usually daytime, but as you've realised it will vary a bit from locale to locale. But it can also be weather system dependant (I don't just mean is it raining) LW/MW propagation can have a major impact especially on those with long and overhead lines and it's also worth noting sunspot activity is currently at a low.
When swapping, leaving the modem/router off for as long as possible, running to hours even is never a bad thing.

[#7]

Here's some info,  that I didn't previously know, I received from Support:
"Unfortunately where we appreciate you do not want to wait for the change to happen automatically, BT will not perform manual SNR changes more than once per line, after that first change (which they are very resistant to do in the first place and only agree to in certain circumstances) if it goes back up they will never do another manually. We apologies for any inconvenience caused."
So be aware, it seems it isn't an easy matter to have your target SNRM changed, and even if you do, you get only 1 shot, so maybe go for the lowest possible, then let it find its own level.

[#8]

What sort of timescale are we talking since the last reduction?
I have heard of this male cow manure before.

[#9]

The previous (only) change was (a Support suggestion) from 15 to 12 on 20 Mar, to get round a sync loss from 1300 to 850 - and it worked.
However, Support have just now said there is a chance that BT may allow a further reduction to 9.....so I'll see if that occurs.

[#10]

Good-o !!  Today, Plusnet Support asked BT to make the change - and 10 minutes later it was implemented.
No waiting around for an Outreach engineer visit!
Excellent, and thanks to Support; so it can be done after all.
...and of course it has increased the sync rate (by 30%)

[#11]

Quote from: jack21

Good-o !!  Today, Plusnet Support asked BT to make the change - and 10 minutes later it was implemented.

Snap! Although I haven't asked for an SNR reset before on this line. I bet one of our faults analysts had to use some pretty aggressive persuasion to get diagnostics to reduce your SNR for the second time in a month!
Glad to hear it's sorted though