Do I have a problem and where is it?

[#1]

I've recently upgraded to Pro (ADSL to ADSL2+), Since the upgrade synch speed has progressively dropped and I think I'm now on a banded profile (sync 6655, att. 25, SNR 17.5). Before the upgrade typical synch was 7k+ with SNR about 10. I certainly had a period 2 days ago with a lot of disconnections because of a hardware fault which is now ok. I'm hoping this is what's caused the banding.
I have some questions.
1) Will I come off the banded profile if I leave the router connected and the connection is stable?

2) If there is something else making the line inherently unstable how do I isolate it?
I have no test socket. The telephone wiring into the house (BT's) is very old. The cable coming in is lead covered to a junction box from another junction box on the outside wall. Extensions are spurred off the interior junction box before the master socket. The cable to the master socket is fabric covered! All of this I assume I can't legally touch but it performed ok under ADSL.
I can't at the moment check if connecting to the master socket helps my sync speed because I think I'm banded. Without disconnecting the wiring I can't isolate the master socket from the extension wiring anyway.
3) Do I need to bite the bullet and pay BT to bring their wiring out of the 1930's.
4) Is there any testing procedure to work out if I do really have a problem or if this is as good as it gets in which case I would be better off on cable.
Thanks
Ken

[#2]

Is there any background noise when you use the telephone?

[#3]

No. Phone seems clear and it did seem to work quite well on  8meg ADSL.

[#4]

Your paying them for a service, report a phone line fault but don't mention your ADSL issues. Then be ready with tea and biscuits and see if the engineer replaces the wiring after seeing its antiques road show quality.

[#5]

6655 is certainly at the top of a band. If your line is banded and if this is because of a hardware fault and your line now remains stable, then you will be 'debanded' at some stage. If this is the first time your line has been banded, then debanding may well happen quite quickly (which means in less than a week). If you're let loose and then banded again later, the banding - in my experience - stays for longer.
It sounds like your wiring scheme is a bit like mine (internal junction box before what is only nominally a master socket), except that mine's not quite so antiquated. You must live quite near to your exchange to have got a 7mb/s sync on ADSL. The higher tones used by ADSL2+ are less robust and more sensitive to line noise. It certainly would help to get your wiring changed, and to get a new master socket with inbuilt filtering - Gus's suggestion sounds like it would be worth a go. I couldn't persuade Plusnet to pay for Openreach to change my wiring, but I was lucky in being able to find someone who knew how to disconnect the bell wire from my (complicated) internal wiring, and my line speed has more than doubled since then.
(My IP profile was 2500 for a long time, but now it's 6500. Mind you, the BT line management software just today did a resync and put me on a a much higher sync and a starting SNR of 3, which is no good to me as the SNR on my line drops by 6 after dark. I've already lost PPP once this evening and I expect it will happen again later. I just hope that when the DLM backs off it will return to a starting SNR of 6, or even 9, but it's possible that my line will be banded again. If so, I'm hoping it will be no lower than the band you may be on.)
Graham

[#6]

I'm coming to the conclusion that the wiring needs changing. It would be nice to know if it really is as much of a problem as it seems before I commit the money.

[#7]

The trouble is, it's hard to tell if your wiring really is a problem without doing proper testing, and you might be charged for that.
Given that you had a good ADSL service for a long time, and that your attenuation is low, and that you thought you'd identified a hardware problem that's now fixed, it might be worth waiting a few weeks (yes, I know it's frustrating) to see if things improve.
If you're brave enough to try removing the bell wire (aka ring wire) from your internal wiring, or if you can find someone competent to do this, that may make a difference. There's info about sockets and wiring here: http://www.kitz.co.uk/adsl/socket.htm.
Graham

[#8]

Quote from: knewmans

I'm coming to the conclusion that the wiring needs changing.

As you've described it I would almost GUARANTEE your wiring is causing problems with ADSL2+.
One "relatively cheap" way to sort out the wiring is to have the incoming cable rerouted to a "proper" (NTE5a) master socket and fit a filtered faceplate.
From there take your broadband by whatever means is best, ideally an adjacent router then LAN/Wireless/Homeplug.
And feed back the phone signal from the new master to the old incoming junction box, and sort it out later at your leisure.
I've seen a few done like that where, on finding a fault, the BT engineer has been "guided" to run a new cable from the incoming drop wire termination to a suitable spot for an NTE5A (usually replacing an existing socket) then use the existing cable to that old socket to feed back to the extension wiring. Minimal effort on his part and then easily sorted by fitting a filtered faceplate.

[#9]

I've left it alone for a while and sync speed has risen to about 10meg as it has been more stable. I seem to be getting about 1 dropped connection a day around 7:30 am - don't know why or if the time is significant. I'll let it run for a while and maybe bite the bullet and get the BT wiring changed.
Thanks