Help Please - Regular Disconnections On Normally Stable Line

[#1]

My broadband connection is usually rock solid, it will stay connected for weeks or even months at a time. Since the 16 September however I have been getting regular disconnections and since the 29 September they have been happening every day:
Sep 16 at 06:41
Sep 16 at 06:55
Sep 22 at 10:52
Sep 25 at 01:27
Sep 29 at 21:42
Sep 29 at 23:38
Sep 30 at 12:05
Oct  1 at 14:33
Oct  1 at 15:20
Oct  1 at 15:45
Oct  1 at 15:50
Oct  2 at 06:34
My speeds are unaffected and a BT speedtest shows that my line profile is still what I would expect (see attached). My setup is a Netgear 834G v3 in modem only mode connected to an Asus RT-N66U so I am unable to get stats from the modem itself. The modem is plugged in to a filtered face plate on the master socket.
As my speeds are unaffected I'm not sure what I should do next. Is anyone from PlusNet able to shed any more light on what may be going on?
Thanks - Bob.

[#2]

Some of those could be BT maintenance and Plusnet maintenance - there's been some emergency maintenance in the daytime recently
These were yesterday:
http://usertools.plus.net/status/archive/1412088088.htm
http://usertools.plus.net/status/archive/1412177901.htm

[#3]

Yes I had seen that and it may explain yesterday afternoon's multiple disconnections but I'm still getting more that usual. Just not used to seeing this many disconnections on my line.
Bob

[#4]

Bob,
Has there been or is there any works being carried out nearby? Gas, Electric or anything of the sort? Perhaps even building work?

[#5]

Hi Chris, you were working late! There has been nothing that I am aware of but they are always digging up the road somewhere so I can't be sure that some work hasn't taken place.
Since I posted yesterday I've had another disconnection at 16:04 on Thursday 2 Oct. Is there any way of telling if these disconnections are line faults (i.e. loosing sync with the exchange), disconnections with Pluset or maybe even just disconnections between my modem and router? Are there any logs at the PlusNet end that could reveal anything? I've attached an extract from my router log if that helps.
Thanks - Bob.

[#6]

Thanks for getting back to us Bob,
This does sound like you have a line fault so I would suggest raising this here so we can get some testing run and see how the line looks and see if the suppler is able to flag anything as a potential cause.

[#7]

Thanks Adam.
I've got to the question where it asks what the light on the router does when the connection drops. The answer is that I don't know as I've never seen it happen but there is no "don't know" answer. What should I put?
Bob

[#8]

Hi bobboulby,
If the connection is stable enough to continue with at the moment I would be tempted to wait for this to drop again and check the lights before answering the question. As I'm sure you can imagine, answering one or the other can lead down a very different patch with regards to the faults process and what we believe is the issue ahead of testing.

[#9]

But as it's only dropping once or maybe twice a day and sometimes at night, I'm unlikely to ever see it.
Bob

[#10]

Hi again bobboulby,
Do you know what the router logs show at the point of the connection going down? You may be able to see if this was a drop in the PPP session or a total lost of sync between yourself and the exchange if you have logs in the run up to the drop.

[#11]

An extract from my router log is in my reply #4. I'm not expert enough to know what it's telling me - I was hoping someone on here would be able to help
Thanks again - Bob.

[#12]

Another two disconnections this morning at 07:45 and 07:55 - I've attached the relevant part of the router log. I wasn't present to see what the modem lights were doing but I've restarted it since to see if that makes any difference.
Just to summarise, since the 16 September, I've had the following disconnections:
Sep 16 at 06:41
Sep 16 at 06:55
Sep 22 at 10:52
Sep 25 at 01:27
Sep 29 at 21:42
Sep 29 at 23:38
Sep 30 at 12:05
Oct  1 at 14:33
Oct  1 at 15:20
Oct  1 at 15:45
Oct  1 at 15:50
Oct  2 at 06:34
Oct  2 at 16:04
Oct  4 at 07:45
Oct  4 at 07:55
Modem reboot on Oct 4. Switched off at 10:28, on again at 10:56
Bob

[#13]

The router logs from the ASUS aren't going to know if the DSL dropped or not because of the separate netgear modem. Unfortunately the netgear logs aren't much better anyway, and the only way to get good ADSL stats out of the netgear is via the telnet interface. If it's not possible to see the modem stats while using the netgear as a bridged modem, perhaps temporarily re-configure the netgear to be a modem/router and re-configure the asus to be just a wireless access point?

[#14]

Thanks ejs, I could reconfigure the Netgear back to a modem/router if that will help diagnose the problem. I'm was hoping that PlusNet would have more idea what was going on from any logs they might hold at their end so I'll wait for their reply on Monday before I pursue this route. My BT IP Profile (from the BT speedtest) seems to be unaffected so that suggests to me that I'm not getting a lot of re-syncs otherwise presumably the profile would have dropped?
Bob.
Edit, what do fibre customers do who have a separate modem and router if they need information about their line stats?

[#15]

I have seen various detailed test results for FTTC fault investigation posted to the forums.
For ADSL, there were a few detailed logs of DLM data posted to the forums not that long ago, which have at least one entry per day, with sync speeds, mean time between retrains, number of retrains (although sometimes the data wasn't particularly clear, reporting multiple retrains / resets without any change in sync speed, or reporting changes in sync speed with no retrains).
I don't know exactly what question the fault reporter asks about the LEDs, it probably presumes you're using a technicolor modem/router which has separate lights for broadband and internet. The DG834G v3 has a single broadband/internet light, according to the manual:

Quote

Blink -- Amber: Indicates ADSL training. On -- Green: The Internet port has detected a link with an attached device. Blink -- Green: Data is being transmitted or received by the Internet port.