Phew !! Lots going on here.
Firstly, as I always state, 'remote faulting' is virtually impossible as there are way too many parameters for mis-information from all parties.
What I find incredulous is that you say you've had a 'Boost' engineering visit, and he found errors and said it was probably a line fault ?? If this
was the case, he
has to continue faulting the circuit until he clears the fault condition causing the errors. I fear that the engineers you have had, may be being overly scrutinised under the ridiculous 'Productivity measures' we have to abide by ??. In the same breath, if they carry out the required tests laid down by all ISP's and OR, and they all pass, then they are well within their rights to 'complete' the job and move on. This really is another debate and one we (engineers) are continually at loggerheads with our bosses with, as it actively encourages poor standards.
So back to your issue. A D-side change of pair is what we book as an 82.7P. There is a historic log kept (for a period of time) by OR of all work done on any SP's line. Before
ANY of the Broadband Engineering visits are built, each line
has to test perfect, ie- electrically fault-free. As B*Cat has mooted, if there was a fault condition detected, then by curing the fault it would normally follow that the broadband speeds/stability would improve.
You say you can hear faint conversations when lifting the receiver on the phone ?? Well, if this is the case then I can assure you when you ring to raise a fault and they carry out the line test, it would return a 'Battery Contact' result of some value between 0-50Vdc. This means your 'positive' wire is in contact with another EU's 'positive' wire (Please, no pedants about -50Vdc etc) and you will be able to hear each others convo's. As you have had Broadband Engineering visits previously, I can draw the conclusion you have got 'Line Tests OK (LTOK) situations at all times.
This leads me to believe that there is an exchange equipment fault on your line, as when the line-test is carried out when you ring to raise a fault, its only testing the 'outgoing' wires from the exchange to your premises in effect, and not going through the exchange equipment (In laymans terms). Therefore it doesn't 'see' the faulty equipment.
As this is a PSTN (Phone) fault, I would be tempted to raise a 'Network Engineering' fault rather than a broadband. When this issue is cleared, then your DSL will improve. Like I say though, this is just my opinion based loosely on the feedback on here. Please give the engineer as much relevant info as you can without getting too complicated. If he's only Network Engineer skilled, ranting on about DSL errors and SNR swings will only make his head boil.
TBH, I would ask if the engineer is 'multi-skilled with ADSL' (the cream of the crop as I can testify to
), and if he/she is, then certainly give them all the info.
I hope you get a result pal, and I do sympathise as a 'LTOK' situation is hard to get anything done with.
