Help with Line Trouble

I've been meaning to post for a while now. Some family members of mine are having major trouble with their ADSL connection and I can no longer suggest or do anything to help.

They have 2 telephone lines in their property. They'd had ADSL with Pipex on one of the lines for a couple of years, and - perhaps coincidentally - everything was great with it until Pipex upped their connection speed from 512Kbps to 1Mb (it was that time when the free upgrades were occurring). As I say, this may have just been coincidental, but they were suffering major disconnection problems, sometimes having no sync for days at a time. Pipex wanted to charge for a regrade back to 512Kbps, and a BT engineer that attended the property said it was the internal wiring. His suggestion - if they didn't want to have their internal wiring messed around with (which they didn't as the house had been recently decorated) - was to cease the ADSL connection on the current line and get ADSL on the other line instead. So that's what we did.

I ordered PlusNet for them. The activation day came, and the connection was up and running, but they informed me that it was unbearably slow. I went round to their house to check it out, and the stats on the router were unbelievably poor. It was sync'd at around 300Kbps (download) and 448Kbps upload. The attenuation was very high (over 50dB) and the SNR was very low (around 9.5dB) given the low sync rate. After double checking that there was nothing unfiltered on the line, unplugging all other equipment one the line, and resetting the router to defaults, I concluded that it must be a line issue.

I contacted PlusNet, and after much arguing, I had to accept their claim that the stats were acceptable and within BT's specification, and that there was nothing that they could do.

But I had one last thought: run a line test with BT, which I did, and I was delighted (!) with the results. It came back that their was a fault within BT's network (not the customer's property like it usually says if there's probably no fault), and an engineer was sent to fix it. I'm not sure what he found, but he said he repaired it, but he didn't think it would affect ADSL.

My family members informed me that the connection seemed better, and I thought we'd finally got to the bottom of the problem. Wrong. It was still slow - not as slow as before - but pretty unusable for most of the time. When I checked the stats, this is what I found (download and upload respectively):

ADSL Link Speed 928 kbps 448 kbps
SNR 9.5 dB 7.0 dB
ATEN 48 dB 31 dB

Furthermore, there were a huge number of FEC, CRC, and HEC errors. Unfortunately, this is how the situation stands today, and has done for a few months now. I don't know what to do next, and I'm hoping that someone here will be able to suggest where to go next.

Many thanks for reading this huge post, and I hope we can get to the bottom of this.

In reply to:

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I contacted PlusNet, and after much arguing, I had to accept their claim that the stats were acceptable and within BT's specification, and that there was nothing that they could do

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If they were telling you that it was ok at around 300kbps sync, then it doesn't sound right to me. Minimum threshold for 8Mg is 400kbps according to BT. But if you are only on 1Meg then it would be acceptable as below.

Line Sync Speed
Performance Threshold

up to 287Kbps 50 - 250Kbps
up to 575Kbps 50 - 500Kbps
up to 1151Kbps 100 - 1000Kbps
up to 2271Kbps 200 to 2000Kbps
up to 8127Kbps 400 to 7150Kbps

Is your exchange on RED.check here http://usertools.plus.net/exchanges/

Have you done a BT speedtest here, http://test.speedtester.bt.com/best done late because it's busy.

john

Thanks for your reply. Yes, the exchange (Barnet) is showing as red. Incidentally, this is also the exchange that I'm on with no problems.

I forgot to mention that I did try the BT speed test, logging on using the btspeedtest login. The results from the BT speed test were very poor (dial-up speeds, IIRC).

How much extension wiring is there on this new line ? The SNR is very poor considering the line attenuation. If the wiring above ground is very long, then it will act like an aerial for noise. My ADSL wiring was picking up the noise from my burglar alarm wiring, until I sorted it.

There's a fair amount, AFAIK. When they had the house decorated, they had extensions put in almost every room. The problem is that there's no master socket to test whether it's the extension wiring.

The long extension wiring will not help at all. ADSL uses the same frequencies as MW radio, and long wiring above ground will act as a great radio aerial, and the ADSL modem will see these MW radio stations as noise, thus severely lowering the sync speed. If the house is close to a MW transmitting station, then the problem will be aggrevated. The idea solution would be to fit a filtered faceplate, but since there doesn't seem to be an NTE-5 socket fitted, then this may not be an option. A lot of benefit can be obtained by removing the ring wire from all the extensions, since this is not required when a phone is fed via an ADSL filter. You should also think about removing unwanted extensions.

Edited by deleted (Mon 20-Nov-06 10:32:40)

Is it necessary to remove it from all extensions, or can I just do it from one?

All.

Stats similar to those experienced by my daughter on a new connection with PN and suggest that connection is maxdsl at the end of a long line from the exchange. You can check this out using www.samknows.com.
Any problems with the internal wiring will only make things worse. To optimise what you have got, fit high quality filters (splitters) to every phone socket with anything connected, disconnect the ring (orange/white) wire in each socket, and connect the router/modem to the filter using a twisted pair cable with RJ11/RJ11 connectors. ADSLNation is a good source of filters and cables.
Visit www.kitz.co.uk/adsl/slowspeeds.htm for advice on the practicalities.
Try a different router/modem (preferably in the master socket if identifiable).
If there is still no improvement you may wish to ask Plusnet to switch the service back to fixed 512Mbs which may well give a more stable service at an acceptable speed.
Good luck!

Thats (broadly) correct. The higher the attenuation of the line, the less wanted signal that actually arrives at the other end, and therefore unwanted signals swamp the wanted ones much more easily. Just one comment - don't rely on the wire colour to identify the ring wire - it's always on terminal #3, but it isn't always orange/white.