Hi Walter,
Unless I'm mistaken this suggests that current services on VDSL profile 17a are actually capped at 39.999 Kbps.
If so, I suspect many excited consumers will be disappointed when their imperfect lines will not achieve 2 * 39.999 Kbps after the "Up to 80 Mbps" commercial arrangements are in place.
That is indeed the case.
It should also be noted that the 39999 Kbps is a MAXIMUM Sync speed.
Some connections are capped by BT's Fibre Centre at a lower Sync speed (for reasons currently unknown) & some are capped by DLM due to line quality/error counts, frequency of disconnections etc.
It appears that for a short while the BT estimating programs were reporting "Attainable Rates", rather than the current capped speed of 40Mb.
A few users on selected exchanges are currently taking part in the 80Mb/20Mb trials.
These users have seen variable speeds between 50Mb & 80Mb, dependent mainly on distance from the fibre cabinet.
At this stage it is unknown what speed estimates would be for lines currently unable to achieve 40Mb from the capped service once the 80/20 service is rolled out.
I believe the ISP ADSL24 has been trialing the 80/20 service for
some users who were previously achieving sync speeds between 15Mb & 40Mb.
I have not yet seen any results from these lower speed trialists, but it would be interesting to see the effect of an attempt to squirt 80Mb down a D-side cable that cannot currently achieve anywhere near the current 40Mb cap level.
Paul.