Look about right.
My down atten is around 18dB and sync at just over 77000 mbps with up having an attainable just over 22000 mbps,
edit:
Now back at PC: Atten 16.5dB with 77360 Down and max attainable 22329 Up. So, your speed is right for the attenuation. I would guess that if you measure your line length it will be around 480 to 500m (actual).
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M H C
taurus excreta cerebrum vincit
Edited by MHC (Sat 20-Jun-15 23:09:46)