Intermittent VDSL disconnections (Possible REIN?)

Hello.

First post here. I'm hoping to get some suggestions on how to diagnose disconnections on my FTTC VDSL service, please. I want to rule everything out that I can before my ISP orders an Openreach SFI engineer with the risk of a £220+ bill if they can't find a line fault.
I know information is important when trying to rule things out, so bear with me as I dispense the lot.

ISP: Uno
Service: 80/20 FTTC (normally 70Mb down, 15Mb up on BT Wholesale Speedtester)
Modem: BT Openreach Huawei HG612 (possibly 1st version, not unlocked, no firmware updates since installation in 2009)

Fault:
- From 10th or 11th May, I've had frequent and intermittent disconnections. The dropouts last for 10-13 seconds, then reconnecting. Usually reconnects on first attempt but sometimes the modem takes 2 attempts to reconnect.
- Disconnections are anywhere from 90 seconds to 4 minutes apart, but most commonly around 2 minutes.
- There have been a couple of periods of extended uptime, but no rhyme or reason to it (have had both mid morning and late night).
- Disconnections continued throughout the weekend.
- When my connection is up for long enough for me to carry out a speed test, my speeds have dropped to 45Mb down, 10Mb up.

Checks carried out so far:
- Eliminated router as problem by connecting 4 different computers (2 x Mac, 2 x PC) directly to modem and connecting through PPPoE.
- ISP say they can't see a problem, escalated it to Openreach who say they can't find any issues on the line remotely.
- I have tried unplugging various bits of electrical equipment around the house, plus I have used an AM radio tuned to 612Khz but I cannot find an obvious source of interference.
- Modem is plugged into a double socket in it's own, both are less than 300mm from master socket.
- Have spoken to next door neighbours either side to see if they have problems but they all have cable broadband with Virgin. They also haven't bought any new electrical items in the past week.

Next planned checks:
- Try another modem (I have ordered a HG612 3B from eBay seller) to establish whether my modem is faulty
- See if neighbours will let me 'scan' their houses with my radio

Background:
- I have had FTTC since BT's first trials in 2009 with no broadband problems at all until last week.
- Semi-detached house on suburban street.
- Telephone line fed overhead from pole. Pole and cable were renewed less than 10 years ago.
- I don't know line distance but cabinet is physically less than 500m walk away.

Could anyone offer suggestions on what other steps or checks I could or should take to isolate the cause of this fault, please?

Thanks in advance for any helpful thoughts.

Edited by deleted (Wed 17-May-17 20:52:50)

I'd start by disconnecting your internal wiring and plugging the modem into the master socket - or, even better, the hidden test socket assuming you have an NTE5 (which has the effect of disconnecting your internal wiring if the NTE5 is correctly wired). Though the socket you're using is physically and presumably electrically close to the master, if there is other internal cabling that might present as a bridged tap and/or a conduit for noise to get into the system.

Get DSLStats installed on a PC and leaving it running - you will need to flash te modem with unlocked software to allow DSLStats to monitor the stats And you could have te information uploaded to an online account at https://www.mydslwebstats.co.uk/

Once you have data and several drops, look for issue just before - does the SNR change greatly, what value does it return to ...

Thanks for responding, David.

I had intended to use the test socket as part of my initial investigations but I couldn't find a micro filter. You have reminded me that I hadn't done this, so I found the filter this afternoon and tried it. Although, the only other socket is a former secondary master socket which is now an extension backwired from the downstairs (and now only) master which is an NTE5C with mk4 faceplate.
However disconnections continued but after about an hour, the line seemed to enter a stable period and I didnt see any disconnections for a number of hours. I decided to put the faceplate back on but the line is still stable, so I'll have to see if it lasts tomorrow.

My line speed has halved in both directions so I'm now getting 35Mb down and 7Mb up but I presume this is down to DLM. If the line is stable from here on out then either the source of interference has stopped or moved on, or would it suggest that there is actually a problem on the line somewhere?

Thanks for responding; once the other modem arrives, I'll feel happier about unlocking one of them in case I end up bricking it or something; having software monitor and log the line is the best thing we need, especially given the nature of the fault.

Thanks

Fine to be cautious ... I have heard of very few that have gone totally wrong. One of mine did not re-flash correctly, however it was recoverable.

Filter not required for testing purposes.

But a way to plug it in to a standard BT socket is needed - filter is often easiest way to do that but you can get cables and adapters that would do the connector conversion.

True, just trying to rule out a filter issue.

Then how would I connect the modem when the test socket only has a BT socket and the modem has an RJ11 plug?

Edited by deleted (Fri 19-May-17 09:52:18)