DLM reset request (ADSL2+)

[#1]

@Mardler

I was wondering why you don't go to FTTC until FTTP is available at your premise.

As I said, I eventually gave up on ADSL2+ because, like you, I was finding it more and more problematical. I started off with ADSL2+ download of 18Mbps/3dB SNR and that was when I turned my router off every night before bed! Years later, after one or two 'events', it ended up permanently banded (albeit at the highest band) for no discernable or explicable reason.

I just checked with the BT Broadband availabilty site for my premises and its quoted "Max Observed Downstream Speed ADSL 14.33/0.89 2022-09-12" Which was me on ADSL2+ at the time. The last recorded speed estimate I have for SOADSL2+ on my circuit is from a print out I have dated 13 April this year, when it was still shown as "Available", which shows "Downstream Range 4.5 To 10 Mbps"!

By then I had already concluded ADSL2+ was effectively obsolete and had had its day, the only way was down. I had re-contracted to VDSL (40/10 Mbps) and am very satisfied with it.

[#2]

pvmb: you sound like our son! I taught him how to build PCs when he was 10, started teaching him DOS, paid for professional tuition (by far the brightest & quickest student his teacher ever had) and he soon eclipsed me! Some 26 years later he is still nagging me about FTTP. Annoyingly, he & you aren't wrong. 😀

Our ADSL2+ connection is fairly stable, at 17.783, for now so it will suffice until decisions are made on location of the new box, which router to use (am thinking the Billion - and connecting the TV by EWAN - for its strong Wi-Fi signal).

I am extremely wary of local OR contractors, one did serious damage to a neighbour's house.

ITM, are you using PN for your 40/10?

Thanks for your comment.

[#3]

The question/complaint/ticket has been closed.

The late night disconnects were traced, with my Sony portable AM radio tuned to 612Khz, to extreme RFI from 4 LED GU10 spotlights which have been replaced by halogens: radio silence, no further disconnects. (As an experiment, turning these lights on during the day didn't drop the connection simply because the SNRM was so high in the 10-13 range.)

With a rock solid connection synced at 17791kbps, on November 9th at 23:25 with a reported SNRM of 10.4 I resynced to give 20227 with a reported c.7.2 during the day. The line has been stable since and the reported SNRM dropping to a low of 5.8 in the evening with the somewhat noisy TV on (the phone line outside runs just above the window behind it!). The Billion modem should easily maintain the connection sans RFI; I see no reason to tweak the target SNRM so will let the exchange DLM do its job.

I have thanked the person handling the situation at PN for first resetting the exchange DLM SNRM to 6db and subsequently monitoring the line including providing me with the relevant charts.

The way the problem was handled was exemplary and an object lesson in customer service.

Thanks too to forum members who contributed helpful material.

Hopefully this stable line will keep us going until the switch to FTTP next year.

[#4]

Really great news and an excellent example of diligent investigation beyond the usual suspects.  One wonders how long those bulbs have (unknowingly) been blighting your broadband experience?  Sometimes the issue is what one least expects.

If you resync around midday you should get the optimal sync speed at a 6dB SNRM.  It might drop a little at night, up to -2dB is to be expected, due to AM radio interference (more so down South than up North).  If the TV adds only a little more, at worse in the absence of anything other issues, every thing should keep trucking even as low as 3dB.

If there is a key lesson to learn and share with others around here, I suggest that it is using modem tweakers can significantly mask the problem which one is trying to manage, making resolution more challenging than it should be.

[#5]

I agree with all of that, TM, bar the last bit.

The Billion modem/router was bought years ago when the line was really bad: disconnects were often every 20 minutes in day time and the line near unusable at night. The Netgear DG834, using an older Broadcom chip, couldn't cope and getting the Telnet bespoke software was a faff so I got something new, The Billion immediately improved the situation and eventually the copper cable faults were repaired. It was only then that I tried tweaking the SNRM and it worked perfectly. Over the last few years it's been excellent, whether the target was set at 4 or latterly 5db the connection was up for 2 or 3 months between power cuts. (We now know that the exchange SNRM was set to 9db.)

I thoroughly recommend the Billion, or even an expensive Draytek, for extracting the utmost d/l speed from ADSL while maintaining a stable connection. 

My takeaway is, short of physical damage to the copper cable, first testing for RFI. It should have been No.1 on my list as I had done it before.

As for the culprit LEDs, I really was surprised. Allegedly, "quiet" ones are available but I can't find any recommendations so we'll put up with 2700k instead of 6500k in the kitchen. Hopefully, I can repurpose the LEDs.

Thanks again for your input and memory jogging.