Profiles again... why does a brief glitch have to be so heavily punished?

[#1]

Thanks for replying Dave.
Router has been in the test socket most of the day. Will do a reset (with another filter) later on tonight when it's quieter.
Cheers for now 

[#2]

Quote from: dave

On the tickets issue, unfortunately if a customer comments on a ticket that is currently waiting to be answered it will push it to the back of the queue, this isn't by design and yes we do want to fix it so it doesn't happen, but the fix isn't a simple thing to achieve. I can't remember off hand what the latest is, but while I've been typing this I've thought of a better way of picking up tickets caught like this than we currently have.

This really does need fixing. I have an intermittent fault that comes and goes very quickly, yet it takes tickets up to 5 days to be answered after updating them - by which point the fault is history and the CS rep replies that BT have found nothing. Also the DLMs 'one size fits all' approach must generate a lot of unnecessary work and irritation for everyone.

[#3]

Still no improvement. Left router switched off overnight, it's the only thing plugged in to the test socket, new (BT) filter:
Line Mode         G.DMT           Line State         Show Time
Latency Type Interleave   Line Up Time 00:00:16:20
Line Coding         Trellis On   Line Up Count 1

Statistics         Downstream Upstream
Line Rate         1664 Kbps         448 Kbps
Noise Margin 16.4 dB                 16.0 dB
Line Attenuation 14.0 dB                 7.0 dB
Output Power 11.8 dBm         12.3 dBm

BT IP profile: 1250K

So how do go about getting the S/N down?
Excuse my ignorance, but I'd have thought a higher S/N would have been more desirable.

[#4]

I think the DMT tool can lower the SNR (until the next router reboot)
What router have you got

[#5]

Using a borrowed BT Voyager 2110 (latest firmware).
My newer Linksys WAG54G wouldn't hold a steady connection when I was moved onto 21CN. I suspect this has caused some of my problems. 

[#6]

Have you tried a different (grey?) phone lead from the filter in the test socket to your router? Is that the same one as you used with your Linksys?
Also does the Voyager give a good connection on its owner's line (to confirm it is not also faulty)?

[#7]

Yes, I'd already changed the gray cable (just in case).
Voyager worked well (as did my Linksys) on the other network, albeit 20CN.
So can someone explain why a high S/N is undesirable, it doesn't make sense to me.

[#8]

OK. Maybe I've answered my own question here.
Am I right in thinking that DLM increases the SNR to an artificial level to compensate for intermitant connections?
If so, as my line has been stable for days now, it should be reducing it, no?
Or am I being naive?

[#9]

I think you are on the right lines.  You'll probably need at least 3 days without ANY resyncs. So sit on your hands! 

[#10]

The problem with a high target noise margin is that the way DSL works that normally results in a lower sync speed (because fewer bits of information can be carried on each frequency, and some frequencies cannot carry anything). However with your 14dB attenuation line, the sync speed available will be capped by the G.DMT protocol to 8128kbps, with spare capacity appearing as increased noise margin. Possibly your 'normal' noise margin immediately after a re-sync would be 12dB, so being 3dB higher than that is not a major problem, and in my opinion concentrating on that aspect is not the thing to do.
To me it looks like there is something seriously wrong with your connection, which from the tests you've done appears to be external to your property. I think you said you had a fault ticket under investigation? What feedback are you getting on that?

[#11]

I'm also of the opinion that it's external as there's nothing left to change!
Only the borrowed router & one phone in the test socket, so effectively ruled out everything else.
I just replied to the ticket yesterday with added information, so I don't expect to hear anything for a day or two. I'll probably wait for another 3 day period and phone them.
At least I've got a reliable connection, albeit running around 1Mbps!