40dB attenuation would be around 3km of telephone line, if you have had it shown from Openreach records this is the line length, then the issue is extra attenuation and possibly dodgy joints from old Al

What is very odd is that most modems when the connection drops and while in the process of syncing you have no IP address and also no ADSL statistics, then the ADSL stats come back after 15 - 30 seconds and then the IP layer after authentication will re-appear on the WAN interface.

The fact you are saying the router is not showing signs of a resync carries the indication the issue may not be DSL related.

If is this not seeing ADSL stats change that is the intriguing aspect as noise drops usually cause the SNR margin to change and when in the first stages of sync you have no adsl stats at all.

Well some of your remarks would justify us taking you at your word, "please treat me as dumb as a gate post and we'll take it from there". Others show you to be intelligent and trying hard to find out what is happening. Let's briefly review what has been said, and some facts.

I have problems with my DSL connection dropping out randomly, especially evenings and also sometimes when the connection is stressed. Sometimes it drops when on a land line voice call. It might be once a day or it might be six times an hour for an entire evening.

Three connected things there. It would be worth your while reading my Noise margin page as you sound as if you may be a little confused by some of the other sources you have read. The essential points for now are that (i) a high noise margin is generally a bad sign, and certainly is in your case; (ii) it is normal for noise margin to fall several dB as daylight fades, and rise during dawn; (iii) it is common for the noise margin to fall one or two dB when the phone is in use.

Besides which, High SNR margin is supposed to be good. It's low SNR that's a problem and <6dB is usually said to be in dodgy territory.

Simply wrong, on all counts. You will see why when you read my page linked to just now, and then this one about high noise margin.

I am on just under 3km of aluminium cable all the way back to the fastest (fibre enabled) exchange in my area.

a downstream attenuation of 60dB represents an incompetent line. Mine is 57.5dB and should be about 40dB for the line length

Aluminium cabling has much higher attenuation than copper. Attenuation is purely the result of line length, material and the circumference of the wires in the pair. It is a measure of the signal loss over its length. Nothing to do with it being "incompetent". Just a fact of life on xDSL.

What I'd like you to try again is getting RouterStatsLite going. I assume you downloaded if from this site - which is the author's. From the routers you have tried and failed with, clearly you have telnet enabled on your system else you wouldn't get failed logins, but there is a tick box in the RSL settings you may have missed. From memory it is called "Special login". What that does is set the router to accept telnet logins. See the "debug" command in the CLI login instructions on this page. That's just for info to you here and now, as we have no interest in CLI access. RS and RSL send that instruction at the start of their login sequence when you set special login, but manage to prevent it opening a blank window.

If you do get it running, please make sure you set the sampling interval to as short as possible. I think it is 7 seconds. That allows us to see rapid noise buildups, whereas a longer interval may not even show a loss of connection - just a state change. Set to save graphs including at closedown. As I remember it I used to manage to get about 1.5 hours per graph. 24/7. It also helps to adjust the sync and margin graphs' maxima and minima to give clearer detail.

Please could you also do as I requested in my previous post, regarding a daytime stats read > router reboot > new stats read. The point partly being we can see what change occurs, but mainly that the noise margin immediately after a router reboot tells us what setting DLM has for it. (Please post the full stats though, not just the noise margin).

If we can also get RSL running that could be a huge bonus. To lose connection when you have a high noise margin suggests a major problem.

One last thought, are you always using the filtered faceplate into the master socket? Have you tried different ones, or a dangly filter into the test socket instead? Filters can fail.

Have you or your neighbour got Sky TV?

I'm deeply indebted for all the input so far, particularly Roberto's and I've put some more time into it in the last couple of days. So in no particular order:

1. I'm still struggling to get anything from RouterStats-Lite. The nearest router to mine on the list is ASUS DSL N55U (mine is a 66) so I've tried that and confirmed that the stats page address is the same. I've also tried the other option for an owner setup and made sure I've put all the info in. In both cases it is definitely finding the modem, because if I leave it at the default 192.168.1.1 it says it can't find it, whereas when I set to 192.168.1.254 it seems happy. But no logging numbers at all, SNR is 0 and download is 3kb. Yes, I have pressed start and yes, Telnet is enabled.

I've run it with and also without the log page up on a separate screen just in case the modem doesn't like to have two clients at once.

Where am I going wrong?

2. Most of the numbers I've been quoting are from the router because they are easy to get instantaneously but I also have them provided by my ISP whenever they run a diagnostic and the numbers are pretty consistent between theirs and mine. The ISP has wound the SNRM up and down several times and as would be expected, lower numbers give me faster speed, higher numbers make it a bit more stable but I still get drops. I had one engineer who said I should ask my ISP to cap my speed at 2Mb and all will be well. They could only offer 0.5Mb as a firm cap but even this would be no use because it falls over in the middle of the night when there is no traffic and even my server is in power save mode.

3. I get two flavours of a failure, both of which have the same effect on my connection. The first is when the modem says "DSL is down, WAN link is down". It then jumps through all the hoops, "LCP can come up" etc. and sometimes it gets back immediately, sometimes it has multiple attempts. Eventually I get "DSL is up", it tries again and in the end I see "Wan Connection: WAN Link is up" and "WAN connection was restored" followed by a connection time which might be a couple of minutes or might be several hours.

The second flavour is when it just says "WAN Connection: Failed to connect with some issues" which leads to "modem hangup" and then on to "WAN Connection: WAN was restored". These are the ones that I am (perhaps wrongly) describing as a loss of sync. I believe my ISP logs them as session failures in the same way as a full blown DSL loss.

4. I'm rebooting the modem as little as I possibly can. In the last set of data my ISP sent me they logged 133 drops in 72 hours, 2 of which were at my end. One was a switch off to put a new socket on the wall elsewhere on the same ring main and the other was when the modem was so confused by about a dozen drops in 2 hours that I couldn't log in so a hard reboot was called for. As I type, my uptime is 7 days, 5 hours 18 minutes and my DSL connection time is 2 hours 19 minutes. A good day, but it will get worse when the sun goes down.

5. Yes, I know that having the fastest fibre exchange in the area is irrelevant. It is pretty galling though. Worse, because I have an EO line, when I get so-called superfast it will be with a cabinet outside the exchange and still the same bit of scraggy aluminium all the way? Is there a replacement policy?

6. Speaking of aluminium, I can only report what an engineer told me when he had all the drawings up on his laptop to show me the route. They were all snaps of good old fashioned hand drawings circa 1995, four years before the Supertram went in. If anyone has access to my local line drawings I'd jump at the chance to speak to you directly but in the mean time, let's assume its Al and does this make any difference to what BT Openreach SHOULD do about it?

7. I'm not alone! There was an engineer in an underground DP around the corner for 2 hours yesterday so someone slightly further downstream than me is probably getting hassle too.

8. My info about acceptable SNR, attenuation and power came from here http://www.screwloose.com.au/hosted-services/broadba... and here http://www.dslreports.com/faq/5862 plus half a dozen similar sites. Hence my belief that high SNR at the modem is good, 60dB attenuation is incompetent and that my downstream power is way, way outside the norm.

Therefore, I'm much obliged for Roberto's link, I've read it will continue to re-read it. The practical fact is that even with the SNR wound out to very good numbers by my ISP and speed dropped as a consequence the blimmin' line still continues to fall over in use and when idle.

9. Yes, I have Sky and so does at least one neighbour. Mine is quite some distance from the modem, fed by high grade PF 100 cable that I routed myself and fed from a professional grade 5x12 multiswitch and a proper quattro LNB on a big dish I erected. It's not one of those horrible Sky dishes with a cheap quad LNB and soggy crimped terminals just begging for a few inches of self amalgamating tape. I distribute its HDMI output to four locations around the house over Cat 6 cable completely separate to my network. Yes, I wondered what you're thinking as well so I turned the Sky box off for a day and it made not a blind bit of difference. By the way, The 3Mp and 5Mp IP CCTV cameras are also on a completely separate network which only connects to PCs using separate NICs.

(I know I said assume I'm as dumb as a post, but actually, I'm not behind the door, as my old man used to say. I just don't know enough to bottom this problem)

Summary

I'd love to get RSL working and provide some numbers if someone can guide me on the path to enlightenment. Meanwhile I'll try the trick of logging numbers then rebooting and re-logging as requested and report back after the weekend. First though, I'm going to speak to PlusNet to see whet their next move is.

And if anyone could humour me for a while and just assume that it's not local interference or my Sky box or my modem and that I'm not making all this up, is there any advice on what BT Openreach SHOULD be doing next, then what after that and finally to sort it?

p.s. It took me so long to type this it went down again. My DSL uptime is now 12 minutes.

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Oops, forgot one.

No, not always been the same faceplate. Started with a (rather expensive) 3rd party one I bought that would allow me to route pre-filtered DSL and voice wiring over Cat 5e 27 metres to my study, where the modem was supposed to sit beside my Level 2 smart switch and the house voice cabling also would connect and radiate. It was sitting on the original 1996 back box.

At the second engineer visit (September) they fitted the very latest BT Openreach Mk 3 faceplate with a brand new back box, new incoming cable and jellies.

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I notice you have an Asus 66, I have a 55 and found the modem part of the router to be rubbish on my line. If you tweaked the line it couldnt hold sync at all so I use the Asus as a wap and router and my billion 7800 as a dumb bridged modem.

Have you tried tweaking the snr margin on the asus or am I barking up the wrong tree here?

On point 8, if you are on a fixed speed service then a high SNR margin is good as lots of room for bursts of noise.

If on a rate adaptive service which you are, you have a choice, have a high SNR margin with lower sync speeds and probably less drop outs.

OR

A lower SNR margin and higher speeds when the line is working, but a risk of more drop outs.

The standard setting of 6dB for the modem to train to is fine for almost all lines, but some need to leave more room for noise bursts.

When a modem says DSL is down that is a sync failure, and without sync you also have an authentication failure, hence WAN link down messages.

If the WAN session drops with the DSL going down which can happen for reasons such as ISP dropping session, or the modem simply having a software error then that is a session drop. If you are having those suggests not that great a modem to be using.

The advice, Openreach has no legal obligation to provide you with working broadband at all, so you can report faults and get them to investigate and risk charges for no fault found visits and after a while they are within their rights to say nothing more we can do and give you a choice, keep service or leave. Put this another way, if you had to pay them per hour at plumbers rates how many hours would you invest in investigating this?

The three modems you've tried are not any of the ones that people rave about on long lines, the 2Wire models used to have a good reputation and may be still around on ebay.

I second Mr S's opinion that a 2wire hg2700 bought off ebay or a good modern broadcom based modem is really the way to go.

In reply to a post by Banger:

I notice you have an Asus 66, I have a 55 and found the modem part of the router to be rubbish on my line. If you tweaked the line it couldnt hold sync at all so I use the Asus as a wap and router and my billion 7800 as a dumb bridged modem.

Have you tried tweaking the snr margin on the asus or am I barking up the wrong tree here?

Happy to tweak it, currently it is +/- 5dB. Should I increment up or down and how far should I change the number?

In reply to a post by ian007jen:

I second Mr S's opinion that a 2wire hg2700 bought off ebay or a good modern broadcom based modem is really the way to go.

Yes, that was my original logic when I bought the D-Link and I planned to use it just as a dumb modem. But it wouldn't play nice with my Netgear DGN3700 router and I had to the D-Link to act as router and keep handling the addressing, DHCP, etc. It didn't have the flexibility for sort of IP things I wanted to do for segmentation of my network and the diagnostics were a bit pants, hence the ASIUS. If I could have found a good modem-only box with no aspirations to be a router I'd have bought it in a heartbeat.

I can see plenty of 2-Wire modems for sale for about a tenner, but they too appear to be modem/router with multiple ports (not sure if they are Gigabit). Will it definitely just be happy to play dumb modem plugged into the WAN port of a router, or would I be treading the same path again? Also, there seems to be a BT business modem with the same model number, is this just a badged clone?

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The good news is that my line appears completely stable for five consecutive days, which is getting close to the record for performance. SNR is 15dB and download is an acceptable 3.5Mb. I have agreed with the ISP to continue monitoring, but it may be that someone has finally brushed the dust off my connection at the exchange and I'm seeing a benefit.

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You could get an HG612 off eBay which although sold as an FTTC modem is in fact a fully-fledged xDSLx modem/router in bridge mode. The default configuration has G.DMT; ADSL2; ADSL2+; VDSL2 ticked, and they are easily unlocked to get line stats or tweak.

Feed your router WAN port from it as per FTTC, and in the unlocked version connect its LAN2 to another Ethernet port on your router to get full access all the time to stats and settings.

Edited by RobertoS (Tue 26-Jan-16 14:18:05)

Will it definitely just be happy to play dumb modem plugged into the WAN port of a router

Yes, just a checkbox and voila, bridge mode.

The 2 wire hg2700 is a bt business model and only 100M Ports I seem to remember.

The ASUS modem chipset/software is know for causing problems....but they are excellent routers