Typical... the day before the engineer came the problem cleared up. It's back in sync at 8128/448 now and the voice service is good. Engineer changed the NTE5 anyway, but all other tests passed. It's been solid for around three days now.

Guess we'll just have to keep an eye on it, and if it does fail again, lets hope it gets real bad.

Thanks again for the advice, it was really helpful.

Hi jaffa_cat,
Glad to hear that your speeds are on the up, sounds a bit suspicious that they should magically sort themselves out the day before an engineer visit, or perhaps someone visited the exchange or manually reset your connection without saying anything........but then BT wouldn't do something underhand like that would they.......LOL
BT were to investigate both contention and capacity issues on my line and responded by..... cutting my speed during off peak times. There was nothing wrong with my off peak speeds, no packet collisions, attenuation was correct however my speeds plunged by around 66% during the peak period times. I had this narrowed down to contention (a fact BT have long known about on my exchange, since at least 2009 to be precise when I first brought it to their attention via Sky) and the fact that there are capacity issues which were publicised in a document on BTs own web site. Orange and BT advised me to log speed checks on speedtester.bt.com which could be checked by both Orange and BT. I have long been suspicious of Bts speedtester and I was proven correct tonight as my partner noticed some severe slowdown and while the Bt speedchecker reported that everything was OK, both thinkbroadband and broadbandspeedchecker.co.uk showed speeds that were a third of my usual speeds. Just dropped another email to the exec office and will wait to see what happens. I am now seriously considering involving both companies ADR and the media because this nonsense needs to stop and stop now. Or perhaps I am better remaining a total thorn in the side of both BT and Orange as my complaints require a large amount of manpower in order for both these companies to louse up so completely, perhaps I will just keep complaining for a bit longer.... Rant Over. Sorry folks. Once again happy to hear that your speeds are on the up jaffa_cat.

Just as a followup, line went iffy again. Seemed to be a lot worse this time, and we were confident we could reproduce the issue when the engineer arrived. Engineer booked, arrived, saw fault occurring and swapped the pair from the pole to the exchange (it's not on a green cab!).

Line is now solid again, and the stats are better than they've ever been:

ADSL Link Downstream Upstream
Connection Speed 8128 Kbps 448 Kbps
Line Attenuation 12.1 dB 4.0 dB
Noise Margin 13.5 dB 26.0 dB

I've got a feeling it's been failing for a while, it's just that the line is so good it's been hanging on in there.

It's also worth saying that since we've been speaking to the guys in the UK, Orange have been fantastic, despite their first line being totally useless.

Thanks once again for the advice given in this thread, we're so pleased to finally have this sorted.