Edit: The normal DSL checker doesn't mention products. It just gives maximum connection speeds. What DSL checker are you using?
Assuming that it's the normal checker and that 52Mb/s is what it's giving for 'Downstream Line Rate' then:
I am expecting fibre to be available at my premesis in the next few months. After looking on the DSL checker, it only states that the 52 mb speed package will be available. Is this because the line is too long to support a 70mb connection?
Possibly. It could also be poor quality cabling (eg; aluminium instead of the more common copper).
Whatever the reason that's most likely the speed you're going to get. It may only be an estimate but they aren't often that far off.
I am around 400m from the cabinet
If your cable covers that distance in a straight line (they usually follow pavements and roads) then I'd say the estimate is on the low side but if the cable meanders a bit then 52Mb/s could be reasonable.
On the basis of that result I'd probably only go for a 55/10 package myself although it's possible that a 76/20 package might get you a faster upload speed.
and the cabinet is about 700m from the exchange.
That has no bearing on connection speed.
Edited by Andrue (Thu 12-Apr-18 16:54:27)