PashuneCaps stifle innovationPremiumReviews:
Fastpath is supposed to set your line provisioned with no error correcting whatsoever. While this does keep your ping rates as short as possible, things like line noise (CRC errors) can now interfere with the line and slow things down or make download speeds appear jittery, which is usually more imminent on longer, poorly conditioned lines. Interleaving introduces higher pings (and slightly less downstream thoroughput), but can be the difference between having a very stable line or having a line that is nearly unusable.
45 ms sounds very high for a fastpath line; anything from 7-15 ms is usually fastpath. You were likely interleaved.
I have achieved 3 meg , fastpath sync on a 15,700 ft. 26 ga copper line. =]