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[idlewilde]

Well, I had to at least *try* to set the atmosphere. 

Background:

The house is approximately 4.7Km from the exchange, or 5Km via road. (Yes, I know!). Due to DACS on the line it has taken over 7 months to get BT to remove the DACS and get the line enabled for ADSL. The line went live about 5 weeks ago. There is not an NTE5 master socket in the premises, but there is an ?LNJ?/?LNR? (help://en.wikipedia.org/wiki/Image:LJ_Front.jpg) socket that feeds directly into an oval-shaped junction box (very old). There are no other sockets in the house. I checked the internal wiring of the LNJ socket, and there are 2 wires connected – 2 and 5.

When I did get connected (using a speedtouch 330 modem) I was online for all of 7 minutes before the first drop-out happened. From there, it’s gotten somewhat worse.

Current situation:

The primary issue is continual, prolonged disconnects. I have tried a USB modem, a SOLWISE SAR600 router, a Netgear DG834 router, and a Linksys router. I think that the disconnects are due to a degrading SNR margin as follows:

Line stats are as follows:

ADSL Link Downstream Upstream
Connection Speed 576 kbps 288 kbps
Line Attenuation 63 db 15.5 db (router bug, I know)
Noise Margin 4 db 21 db

The SNR varies between 8db all the way down to minus figures (the lovely 21443567 eleventy1 number) over the space of minutes, hours, and so forth. The upstream attenuation on the Solwise router reads 63db (the highest it will go), and 15.5db on the Netgear router (known bug, I know). I have seen the SNR drop to -4 (no, not a typo) and then disconnect, and eventually re-synch at a later stage with a varying SNR value.

There are no extension cables being used, the router sits about a foot away from the LNJ socket, and I have tried 5 sets of filters, from the cheap to the relatively expensive.

When the router is connected and synched, if the phone is used, the connection drops out, and the SNR goes nuts. It can go up to 12db, and then steadily drop to -4 to 1-2db, or it can stay around 7 – 8db until the phone is put down, after which it progressively degrades down to 1 – 2db (or minus figures). I’ve done the quiet line test and it reported no errors, asked BT to check the line and they reported no errors, however, if I pick up the phone to an open line, I can hear the router trying to connect. High-pitched, faint, but audible.

If, as last night, I leave it connected, it stays connected for about 1 – 2 hours, and then loses synch for hours on end.

The ISP:

I am using Virgin Media on the 2Mb package (I know), and have raised 4 faults in the last 2.5 weeks to try to get either an Openreach or an SFI engineer onsite to do line checks with a Hawk/Mole/TDR, but Virgin are closing the tickets without informing me. I am supposed to be getting a call back from level 2 technical support today (pigs may fly) so I can speak to someone, convince them of my situation, and get them to arrange an engineer’s visit.

Summary:

I am aware that the length of the line is going to be a mitigating factor, but I am at a complete and utter loss as to why the synch varies so much. I know it could be a potential high-resistance fault, it could be a REIN fault, it could be a wiring fault, and it could be due to rarefaction of sunlight off the grassy fields that surround my house. (Ok, maybe not the last one.) I have used different filters, cables, routers, flashed hardware to the latest version of firmware, dressed up as Marilyn Monroe at 12am under a full moon, and sacrificed field-mice to the broadband gods, whilst crooning “Happy Birthday Mister President”, but to no avail.

As I say, I am awaiting a call from Openreach to ascertain what is going on, but I was also hoping that some of the esteemed and learned people here may be able to cast their eye over the above treatise, and hopefully let me know what I should do/shouldn't do.

Many thanks for reading this far.

[Ezzer]

the 63db indicates the line loss is 63db or greater, hardly any modems /routers will display any figure over this regardless of the actual figure. The fact it's taken so long to dedacs you dosn't bode well.

The only other thing is the oval box, about what size is it roughly. because if it's bigger than 2"x3" then it may be a 15a filter or similar which can drasticaly increase the attenuation and typicaly stop sync altogether, (in which case a definate engineer visit to sort) other wise again an engineer visit to upgrade your nte (sounds as if it's an lju 2/1) to an nte5 just for practical reasons alone, and to check out if there is a pair of wires (typicaly e-side in other words from the exchange to the cabinet/pcp, the green boxes you some times see) with a lower line loss.

The 5km by road is usualy the best guide as to the probable cable distance assuming the exchange you have in mind is the actual one your fed from. and the cable route may be much more conveluted than following an approximation of the road route. I can think of plenty of places I know where the above 2 senarios apply.

Hearing the "handshake" through the phone when the modem is trying to sync is not unusual regardless of filters, after a few seconds this goes into "training" where the modem and exchange are trying to talk from the same page, this can sometimes be heard but not that typical, certainly when you get sync you shouldn't hear anything.

Sync dropping out when using the phone can be caused by a number of factors, if not the phone then capacitance inbalance which is typicaly caused by internal wiring/sockets,apperatus but can some times occur on the network. Other wise if the line loss is that high that your absolutely on the limit of getting sync then a little disterbance inevitably causedby the lopp on the line due to the recever being lifted can have this effect, the only way of finding out is with a router that can display >63db loss (drayteck is one I know can) or with an openreach engineer running an apts test, note the familiar theme in this case.

Keep persevering with your isp, good luck 

[roseway]

Hi and welcome

I don't know that I can add anything to what you've already done and concluded. The reported attenuation of 63 dB is the highest value which most routers will report, so it could in fact be even higher. A line like that is always going to be difficult. The fact that the connection drops when you pick up the phone certainly suggests a line fault, and I think that your best option is do what you're already doing (but maybe leave the field mice alone ) and keep pursuing it with your ISP.

[Edit] Ezzer got in first while I was writing this, but I'll leave it anyway.

[Ezzer]

Soz Roseway, spent a while typing whilst waiting for a new fix on my work laptop to close my last job off and log me off successfully in a long time.

And it's worked  (at least thats some thing) (Oh no, I know I've just cursed it havn't I and I'm in on sat again, Please no more automatic updates  )

[kitz]

From your post you've already done a lot of research into this and done all the right things you can yourself. - Im quite impressed


You quite rightly summise that the length of your line will have a large bearing on this (62/63dB is  the highest figure most routers will report and there is the possibility that your line has a higher attenuation).  Youve even researched the known bugs regarding this and how the minus fiugres are displayed.

The area you perhaps need to focus on IMHO is the fact that the line drops when the phone is in use and the large fluctuations in SNRM. I would also be stress to your ISP that you have LJUs As you are on a very long line you would likely benefit from the installation of an adsl filtered NTE5 unit, which BT are supposed to fit for free on troublesome and long lines.

The line is far from stable and therefore is best suited to be looked at by an adsl engineer.  Unfortunately it would appear that the problem is getting your ISP to arrange a visit.  Many ISPs these days are loathe to send out an Openreach engineer due to the possible fee of £150 plus VAT if the fault is found to be with the customers equipment.

[idlewilde]

I just wanted to say thank you so much for your respective responses. I appreciate this like you would not believe, as it lends credence to the fact that I am not going insane!

I am trying my utmost to get an engineer onsite to review the setup, as I firmly believe in perseverance, and I do not intend to give up until I know that an ADSL connection to the house is physically, and electronically impossible. A neighbour 40m away from the house has a fixed-rate 1Mb line, so I hope that I can at least get 512k to here.

Ezzer - the junction box in question is about 3.5" long, by 2" wide. I can't get into it, as some luadramán has been kind enough to paint over it, and effectively fuse it shut. 

I have also been informed that there is indeed a fault with a cable near the premises, and despite a BT engineer locating and diagnosing said fault, he needs to get hold of a specialist (allegedly there are only 2 in the West Midlands area that can do this?) to fault-test the line, and potentially replace the faulty section of cable. I am supposed to get a call back from Virgin next week ( ) to arrange to get an engineer out here, so in the interim period, I will chuckle gently at an SNR value of -7. No, not a typo, Routerstats logged a value of -7 at 4:23am last night.

Surely I deserve the  title of "Worst phone line in the UK"?

[kitz]

Wow I don't think I've seen a -7 before now.  -3 is the lowest Ive seen before the router gives in and looses the connection.

All credence for your router for "hanging on in there"..  but TBH I should imagine that if you'd tried to use your connection at that point it would have been hideously slow and practically useless due to a large amount of errors and dropped data packets.

Continuing to push your ISP for an Openreach engineer is the way to go.

[Ezzer]

Sounds too small to be an old style alarm filter, there is a knack to getting the lids off without breaking them after they've been glued in with paint.

Sounds as if some one has asked for a pto to test the line which whats required if for instance there's an arkward "battery" fault which you can't locate precisley with a megger or hawk

[idlewilde]

Thanks, everyone. As soon as I get an update from Virgin, and get an engineer onsite, I will report back, if this is ok.

Would it be safe to assume they will go to the exchange first, and then potentially do a home visit? Would vast amounts of tea/coffee and jaffa cakes be condusive to the visit? 

[Ezzer]

I normaly start from the exchange because if the problem is there then it saves chasing non existant problems out to the network.

Teas and coffiee's are lovely, but scuse me before I look at any other posts as I need to go to the loo right now. 

[idlewilde]

Now this has gotten interesting!

Despite Virgin not sending an engineer out to the house, and my being unable to connect to t’interweb since Saturday afternoon, something incredible has happened.

I cadjoled Virgin into sending me a DG834G router, and last night when I got home, plugged it in, and got online immediately.

The SNR Margin was 14.3! It remained perfectly stable (within 0.25db) for over an hour, and then things went back to normal. SNR margin dropped to 3.9db, and then hopped up and down (between 7db to -1db). I then rebooted the router, and left it when it read 13.8db at about 8:00pm last night and went to visit the land of Nod.

When I came out this morning to check on it, it had (brace yourselves) stayed connected over 10 hours! The SNR margin had stayed between 13.8db and 15db all night!

Shocked is not the word. I think that as per my last post about BT having acknowledged a fault with a section of cable, that they have repaired it and then some.

I am still chasing Virgin to send me an engineer so I can get the NTE5 faceplate installed, and also get someone to do a test on the line to make sure all is well, but flipping heck, what an improvement!

Thoughts?

As an aside, I did a check on the phone number and postcode this morning, and whereas it used to tell me I might be able to get 512k at a push, it now says:

BT Line Speed Estimation    

   Fixed ADSL:    2048 kbps   (2 Mb)
   DSL Max :     6500 kbps   (6.5 Mb)
   

Up to 6.5Mb nearly 5 miles from the exchange? Yeah, right!

[kitz]

Obviously I'm not 100% certain, but I would guess that the new router may have had a little bit more to do with  your line remaining connected than an actual fix being applied.

Reason I say that is there was still a fairly large fluctuation from 14.3dB down to -1dB at one point.
The netgears do have a very good history of being able to perform well and hang on in there on some long lines.  Out of interest have you checked on the bottom of the new router to see which version of the netgear Virgin have sent you out.  Its probably a DG834G v4 with the broadcom chipset, compared the older DG834 v3s which had an AR7 chipset.

[idlewilde]

Apologies about the hotlinking, but I've dragged out my Etch-a-Sketch and made a lovely drawing of my SNR margin.

If this is against the forum rules, please let me know.

Kitz - you are right. It's the router, not the line.

Starting to lose the plot here.

[kitz]

>> I am still chasing Virgin to send me an engineer so I can get the NTE5 faceplate installed

I think youre going to have to continue to chase that with your ISP Im afraid. :/

You could also look at REIN faults.  I'm not 100% convinced that it is wholey attributable to typical REIN, but the instance on your graph which shows a possibility is the sudden dip from a stable 8.5dB down to 3.5dB. ...  and also the spikes between 5dB and 0dB just shortly before your router lost sync.

[idlewilde]

Quick update. Despite being told I was guaranteed a callback regarding the situation, no call materialised. I called them last night, and spoke to someone who told me that BT have acknowledged a fault on the line, and the next step is to arrange an appointment.

Hopefully by Christmas (2009) this issue may be resolved.