In uk.d-i-y, Harry Bloomfield wrote:
Mike Barnes was thinking very hard :
In any event you get best performance by putting the "modem" as close to
the exchange as you can get it.

I'm very close to our exchange at 0.6km, but I doubt even extending
that another 60m on twisted pair even to the far end of our garden
would make any difference at all.

I wouldn't be so confident.

--
Mike Barnes