Sounds like a great engineer, so basically he tried swapping all of this in a single visit which is very good of him.
Tie pair swap
D side swap
DP swap
Did he do a DLM reset before trying these alternate pairs?
I just read all your posts.
The AAISP line is syncing higher presumable due to a lower target SNRM. It may also have more favourable conditions in terms of quality of the line and crosstalk, someone would need to try and calculate what the line would get on equal line parameters to the infinity line.
The infinity line if you leave it alone as long as its stable should eventually end up on a 3db target as well so the speed would increase.
Yeah, he was a good one. He spent about 3/4 hrs, up the pole, walking to the different chambers in the path etc. He reset DLM a couple of times and actually sat with his tester in my master socket for what felt like ages, it only ever showed up 1 fec error in about 10 mins! He did everything he could, so I’m happy with that.
I think my gamble has paid off with my AAISP line though - I've lucked out a bit I think, if I disconnect my BT line my attainable on my AAISP rises to 84Mb, 32mb up. So my 'BT' line is seemingly more susceptible to crosstalk than my new one.
So I've contacted BT today and they have confirmed that I am free to end my contract with no penalty as my minimum in contract is 57mb - so I shall be doing that and will then have a single line on 70mb+ with AAISP...!
p.s - I'm on ECI, so 6db SNR will be my norm. When my AAISP line resynced when he was doing the work, my BT line was off - so my AAISP came up at 78mb on a 6db SNR. When my BT line came up....my attainable on AAISP dropped quite a bit and my SNR fell to about 2....so although it seemed stable, to be safe I've resynced my AAISP to get it back to the 6db SNR and in line with the 64mb sync - but that'll gain 10/15mb when my BT line goes.