Hi Meditator (Sorry about the wrong name)

That's a good point, I will check the wiring. I'm pretty sure I used a Krone tool, I certainly do now.

Okay, here are the readings:

With ADSLNation faceplate:

adsl status
--------------------------- ATU-R Info (hw: annex A, f/w: annex A) -----------
Running Mode : G.dmt Annex A State : SHOWTIME
DS Actual Rate : 4928000 bps US Actual Rate : 448000 bps
DS Attainable Rate : 5088000 bps US Attainable Rate : 1172000 bps
DS Path Mode : Interleave US Path Mode : Interleave
DS Interleave Depth : 32 US Interleave Depth : 4
NE Current Attenuation : 50 dB Cur SNR Margin : 9 dB
DS actual PSD : 19. 9 dB US actual PSD : 12. 3 dB
NE Rcvd Cells : 936 NE Xmitted Cells : 454
NE CRC Count : 1 FE CRC Count : 0
NE ES Count : 1 FE ES Count : 0
Xdsl Reset Times : 0 Xdsl Link Times : 1
ITU Version[0] : b5004946 ITU Version[1] : 544e0000
ADSL Firmware Version : 05-07-02-08-00-01
Power Management Mode : DSL_G997_PMS_L0
Test Mode : DISABLE
-------------------------------- ATU-C Info ---------------------------------
Far Current Attenuation : 26 dB Far SNR Margin : 23 dB
CO ITU Version[0] : b5005453 CO ITU Version[1] : 54430000
DSLAM CHIPSET VENDOR : < TSTC >



Into test socket:

adsl status
--------------------------- ATU-R Info (hw: annex A, f/w: annex A) -----------
Running Mode : G.dmt Annex A State : SHOWTIME
DS Actual Rate : 4704000 bps US Actual Rate : 448000 bps
DS Attainable Rate : 4896000 bps US Attainable Rate : 1140000 bps
DS Path Mode : Interleave US Path Mode : Interleave
DS Interleave Depth : 32 US Interleave Depth : 4
NE Current Attenuation : 50 dB Cur SNR Margin : 9 dB
DS actual PSD : 19. 9 dB US actual PSD : 12. 2 dB
NE Rcvd Cells : 1313 NE Xmitted Cells : 1430
NE CRC Count : 1 FE CRC Count : 0
NE ES Count : 1 FE ES Count : 0
Xdsl Reset Times : 0 Xdsl Link Times : 2
ITU Version[0] : 00000000 ITU Version[1] : 00000000
ADSL Firmware Version : 05-07-02-08-00-01
Power Management Mode : DSL_G997_PMS_L0
Test Mode : DISABLE
-------------------------------- ATU-C Info ---------------------------------
Far Current Attenuation : 26 dB Far SNR Margin : 22 dB
CO ITU Version[0] : b5005453 CO ITU Version[1] : 54430000
DSLAM CHIPSET VENDOR : < TSTC >

I'd say that those figures, in both cases, are about what you'd expect for your situation. In fact, they're not too far removed from what I had myself, before I moved to an FTTC connection. If anything, the downstream SNR figure is possibly a bit low, ie. a bit hopeful. I used to have a stable 4M bps ADSL connection working at an SNR of between 12 and 15dB. Owing to the type of router I was/am using (Broadcom chip), I was able to manually set the target SNR.

I think it's the case (and I'm sure certain correspondents will correct me if I happen to be wrong) that, to achieve a stable ADSL line, you can either get your ISP to change the Interleave Depth outside of the default value 1 (Fast), and clearly that's already the case, or instead you can, if your router allows you to, yourself alter the line's target SNR. (It's possible to do both, but you then run the risk of the line's SNR effectively ending up out-of-range and the line reverting to 2M bps). A 9dB SNR for a line with your characteristics seems to me to be somewhat working on the edge. It might be that over the last 9 years you've been particularly lucky in your line remaining stable at the sort of speed at which you're running but that something may have recently changed (more local users, say) to have put the SNR value over the brink. Perhaps there's a need for you to leave it a bit longer, to see if a revised Interleave Depth or SNR is obtained?

IMHO, nothing you've given us points to a failure of the faceplate filter.

Thanks for the feedback. Well at least I know it's not the faceplate. As far as I'm aware the Draytek 2860 doesn't allow me to alter the SNR.

I have noticed that the connection drops occasionally overnight, is this normal? In the past I never took any notice of that as I wasn't having any problems.

I'm afraid most of what meditator has posted is incorrect. As you can perhaps see from what IDNet have already tried, which is the opposite of his suggestion.

Far from the SNRM being low, it is 3dB above the normal 6dB. That suggests there has been instability, which you have just described is still happening.

When you get disconnections like that the system (DLM = Dynamic Line Management) raises the SNRM in 3dB steps to try to prevent them. The fact that meditator needs a 12dB or 15dB setting to stabilise his indicates severe problems somewhere. Possibly a faulty line, possibly it passes by a source of high electromagnetic noise between him and the exchange. There can be many reasons.

Each 3dB step up in margin costs you often around 1Mbps connection speed, and sometimes more. That's where your speed has gone. With your 50dB downstream attenuation I would expect several hundred Kbps more, depending on all the other line-affecting factors.

If you want a bit of background, then read my Noise Margin page, and also from the left-hand menu there read Troubleshooting >> High noise margin. Particularly Section 4.

From your change to using a dangly filter in the Test socket, at this stage we are told nothing by the very similar results. In particular it could still be a faceplate filter problem. I/we were looking for a significant difference in the two sets of stats, and there isn't one. A big difference would have suggested a problem with the extension wiring or some piece of kit connected to it.

Do you use the landline phone at all, and if so which socket is it plugged into? The phone socket on the faceplate, or at an extension? How big a problem would it be to you to have the extensions not working for 2-3 weeks?

The 2-3 weeks is for DLM to restore the 6dB margin if it is a faceplate problem, as explained in my links. If it is some other cause then things will stay as they are or continue to deteriorate.

The best thing to do if you need the extensions connected would be to replace the faceplate anyway with a new one, that you could connected the extensions to. We can tell little until we get this 2-3 week wait.

Having said that, if the disconnections stop now you aren't using the faceplate then we are close to knowing it is a local problem.

Far from the SNRM being low, it is 3dB above the normal 6dB.

Yes, but "normal" assumes you're fairly close to the exchange, and if andyfr's stats are to be believed he's not. If, as any user, you insist on screwing as much speed out of the connection as possible and operate at a low SNR in a situation where you're a fair distance from the exchange then you've got to expect that on the odd occasion or two noise will intrude and produce errors.

Whilst you're correct in stating that I myself had "severe problems" when I was on ADSL, please note that that's now ancient history, as I'm now operating on VDSL (an FTTC connection) for the same premises-to-exchange connection and no longer suffer the severe interference problems I had. So "needs" in your reply should read "needed". The point in the premises-to-exchange connection where those problems occurred is now covered by optical fibre, completely eliminating the issues I had when on ADSL, and my current connection therefore can fully sing. Pre-FTTC, there was absolutely nothing that I myself could have done to achieve stable operation, save to operate the line at an elevated SNR.

As for andyfr's stats, I still contend that his situation is similar to what I used to have, at least in so far as downstream speed and attenuation goes.

My advice to andyfr is that, if after further investigation, he suspects that the problem does lie in the faceplate filter, he specifically gets the Clarity version as a replacement.

The 'Yes, but "normal" assumes you're fairly close to the exchange' is something that is contestable, since plenty of people do benefit and are happy with the standard 6dB or even benefit with the lowest 3dB.

if the issue is the faceplate, then running from test socket for a while will reveal if there is anything to be gained.

Agree, my line used to run happily at 3dB on ADSL2+ and it is over a mile long.

In reply to a post by ian72:

Agree, my line used to run happily at 3dB on ADSL2+ and it is over a mile long.

It can become something of a balancing act with ADSL: just recently I've had a few issues with my line and to achieve a stable connection with optimal speed I've forced ADSL2 and a 3dB downstream SNRM - previously ADSL2+ with a 6dB SNRM and 37dB attenuation. Haven't lost much throughput speed though ~10.3Mbps reduced to ~9.3Mbps and I can live with that for the time being

Unfortunately it is of little relevance to the OP since he is on ADSL1(G.dmt Annex A) with a 50db attenuation and to reduce the SNRM from 9dB could make the connection unstable. If it is/was a problem with the filtered faceplate then hopefully his line should stabilise with perhaps a 6dB downstream SNRM and a slight increase in throughput.

I think for the cost it's worth getting a new faceplate anyway. I did try to find the recommended Clarity one without success, so I will probably go for another ADSLNation one unless there is a better alternative.

The main phone is plugged into one of the extensions so I need to keep that option. I have also ordered a better quality modem cable as well.