Sorry, another OT post on an ADSL subject - if anyone has some suggestions of decent technical ADSL lists or forums please let me know.
One of our customers migrated from one ISP to another, from a reasonable speed (3-4Mbps we think, it as never an issue so they never made a note of what it was), which immediately on migration dropped down to silly figures - their BT speedtest results hover between 100kpbs and 200kbps and their most recent result was 40kbps!
Despite numerous faults to BT via the ISP, little has changed to date (the migration was in May!); apparently they changed the linecard yesterday and it seems to have been that the change to the linecard is what has given the end user the record low speed of 40kbps. The IP profile for the line is 7150Kbps, and their sync speed is over 7Mbps, and their upload speed is around 800kpbs. (Bandwidth figures for the connection tie in with this data, so it's not as if there's some underlying data transfer that's tying up the connection somehow.)
We've changed the end user kit and filters (although bear in mind the original kit was working fine pre-migration) to no avail. Speed tests using different accounts (eg test accounts at the ISP, or bt_test@startup_domain, etc) all give similar results.
I need to find someone who has seen something similar and has some sensible suggestions as to what to try next. (Is the fault likely at BT or the ISP?)