Connection Dropping

[#1]

Over the last week my connection has been intermittently dropping. It can run quite stably for hours with reliable download speeds of approx 12Mbs. The disconnection may be worse in the evening at peak times but I can't really confirm this, I've tried a new microfilter and have now plugged directly into the test socket with no phone connected to the microfilter - so everyhing should be isolated with and I still get dropped connections.
I've logged sync speeds and noise margins over a few hours and there seems a definite trend of noise margin reducing  over a minute or so just before the connection drops.
Any idea what's going on?
I saw the service status report last Friday about peak time problems and I think my problem started round about then.
I've attached a log of the router stats if that helps - at least I tried to but .txt files aren't allowed, so here is a snippet.

Sat 18 Feb 2012  11:51:11,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:51:26,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:51:41,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:51:56,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:52:11,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:52:26,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:52:41,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:52:56,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:53:11,    Noise Margin= 2.8, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:53:26,    Noise Margin= 3.2, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:53:41,    Noise Margin= 3.2, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:53:56,    Noise Margin= 3.2, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:54:11,    Noise Margin= 3.2, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:54:26,    Noise Margin= 3.2, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:54:41,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:54:56,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:55:11,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:55:26,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:55:41,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:55:56,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:56:11,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:56:26,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:56:41,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:56:56,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:57:11,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:57:26,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:57:41,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:57:56,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:58:11,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:58:26,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:58:41,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:58:56,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:59:11,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:59:26,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:59:41,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  11:59:56,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:00:11,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:00:26,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:00:41,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:00:56,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:01:11,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:01:26,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:01:41,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:01:56,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:02:11,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:02:26,    Noise Margin= 3.0, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:02:41,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:02:56,    Noise Margin= 3.1, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:03:11,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:03:26,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:03:41,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:03:56,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:04:11,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:04:26,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:04:41,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:04:56,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:05:11,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:05:26,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:05:41,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:05:57,    Noise Margin= 3.0, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:06:12,    Noise Margin= 3.0, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:06:27,    Noise Margin= 3.0, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:06:42,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:06:57,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:07:12,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:07:27,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:07:42,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:07:57,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:08:12,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:08:27,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:08:42,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:08:57,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:09:12,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:09:27,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:09:42,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:09:57,    Noise Margin= 2.9, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:10:12,    Noise Margin= 2.4, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:10:27,    Noise Margin= 2.4, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:10:42,    Noise Margin= 2.3, Sync Speed= 16935, Up Speed:  448 kbps
Sat 18 Feb 2012  12:10:57,    Noise Margin= , Sync Speed= 0, Up Speed:  kbps
Sat 18 Feb 2012  12:11:12,    Noise Margin= , Sync Speed= 0, Up Speed:  kbps
Sat 18 Feb 2012  12:11:27,    Noise Margin= , Sync Speed= 0, Up Speed:  kbps
Sat 18 Feb 2012  12:11:42,    Noise Margin= , Sync Speed= 0, Up Speed:  kbps
Sat 18 Feb 2012  12:11:57,    Noise Margin= , Sync Speed= 0, Up Speed:  kbps
Sat 18 Feb 2012  12:12:12,    Noise Margin= , Sync Speed= 0, Up Speed:  kbps
Sat 18 Feb 2012  12:12:27,    Noise Margin= 3.1, Sync Speed= 16852, Up Speed:  445 kbps
Sat 18 Feb 2012  12:12:42,    Noise Margin= 3.1, Sync Speed= 16852, Up Speed:  445 kbps
Sat 18 Feb 2012  12:12:57,    Noise Margin= 3.1, Sync Speed= 16852, Up Speed:  445 kbps
Sat 18 Feb 2012  12:13:12,    Noise Margin= 3.1, Sync Speed= 16852, Up Speed:  445 kbps
Sat 18 Feb 2012  12:13:27,    Noise Margin= 3.1, Sync Speed= 16852, Up Speed:  445 kbps
Sat 18 Feb 2012  12:13:42,    Noise Margin= 3.1, Sync Speed= 16852, Up Speed:  445 kbps
Sat 18 Feb 2012  12:13:57,    Noise Margin= 2.9, Sync Speed= 16852, Up Speed:  445 kbps
Sat 18 Feb 2012  12:14:12,    Noise Margin= 3.1, Sync Speed= 16852, Up Speed:  445 kbps


Thanks

[#2]

Is that noise margin set by the exchange or have you tweaked it lower manually?

[#3]

That's the margin reported by the router. I haven't made any changes manually
I've just noticed another drop to 1.2dB and then recovery. Connection didn't drop this time though.

[#4]

Plug in the phone only and use the quite line test [ dial 17070 option 2 ]and see if you hear any white noise/crackling, also if you can with another phone to confirm if you do on one then report it to who ever supplies your phone.  Had the same thing last week and came down to either a faulty master socket or the line to the pole outside my flat.  Engineer did some work on the pole and changed the master socket for good measure.

[#5]

Quiet line test with the modem disconnected is - quiet.
With the modem connected I can hear white noise & clicking in the background. I've tried this with two different micro filters with the same result.
If I switch the modem off the noise continues for a few seconds -suggesting it's coming from the exchange?

[#6]

Would say that points to the router, so if its a PN supplied router get a tester/replacement sent out or use another if you have a spare.  If not when BT come they will charge for the call out if its your router at fault.

[#7]

If it's the router, why does the noise continue for a few seconds after I turn it off? PSU Capacitors won't give that kind of hold up time.
Anyway at about 9:30 this morning my SNR margin jumped from 3dB to 6dB and everything has been stable since then. Sync speed has dropped slightly but average download speeds are still as fast as they were - so if nothing changes I'm happy again

[#8]

@disgruntled
Raise a <a href="https://portal.plus.net/apps/kbdfaults">fault</a> if that starts to be a problem for you as it can be indicative of a jumpering issue at the exchange.

[#9]

Thanks Adam, I already have a ticket open on this.
So far they have helpfully suggested changing microfilter and connecting to the test socket, both of which I had already done previously and reported the results . Seems odd that I couldn't actually raise a ticket for this without going through the checks (or at least saying I had) only to be asked to do them again. As I said things have been fairly stable since the noise margin increased - is there any way to check if there is a jumpering issue at the exchange?