Lots of engineer visits/changes and still not fixe...

Question

I have had 3 visits by engineers now and they have done a few things but my broadband is still unstable...
My adsl has been stable for over two years with 2mb+ at all times and about 2 weeks ago this all changed.
Now I see hundreds of thousands of CRC errors on the down (even when I am not using it) at random times of the day. This happens pretty much every 12-24 hours but never at a consistant time of day.
The internet becomes unusable when this starts happening and can take many hours to recover, it does however recover eventually.
The engineers have done this so far:
Replaced my router and put a new filter on
Checked the line many times when they come, no errors
Moved me onto another line, speed improved but errors came back
Moved my equipment over in the exchange
Being an intermittent problem I understand it is hard to find and the engineers have ruled out quite a lot.
I doubt it is anything in my house as there is nothing new going on.
There are no useful stats to show at the moment, as I said all that happens is the CRC errors will start and go up in their thousands per second. I may add that when this starts happening the line speed fluctuats from 800k-2mb down but it is unstable.
All the obvious things my side have been ruled out, many routers tried, many filters, many cables, no difference.
I hope somebody has some clue about this because my internet is pretty useless at the moment and I need it because I work from home sometimes (I am a web developer).
On a side note they said our exchange is going fibre optic early next year, would you know if this would fix the problem or not? I know that the copper wire will still be used and this is most likely the problem.
I am contacting virgin to get cable as we speak because I doubt this problem is going to solved soon, if ever and I need the internet badly.
Cheers for any advice,
Mark

Answer 1

Well to be honest, you're on a long line and the attenuation difference, isn't anything of major concern, on a line as long as yours any little variation in temperature or environmental factor can alter the attenuation.
Here are some helpful (I actually did find them helpful!) tips from BT: http://bit.ly/mSl9SB
As standard, the bell wire should be taken out of any master or extension socket as this can reduce the amount of interference your broadband can pick up and sometimes fixes the problem, see how to remove it here http://bit.ly/qc3bZ4
There may also be some other stuff you wanna check out like what affects your broadband inside your home: http://bit.ly/ukwBFb
Also try a tidy up of your cable as per this users (RogerB) post : http://community.bt.com/t5/BB-Speed-Connection-Issues/Poor-Broadband-speed/m-p/14217
You can also have a look at my post re: Best way to get speed out of your long line http://goo.gl/ddnG2
Regards Edd
Check your Line
BT Speedtester