After months of poor upstream sync speed on my BT VDSL connection, in desperation, I obtained a asus dsl-n66u to see if that routers "upstream power back off" (UPBO) setting could improve my upstream sync speed.
The following screen captures show the routers connection settings I tried and the resultant router stats (or what passes as stats from this router)
Asus1:
UPBO: disabled / Stability Adjustment (VDSL): 5dB / Dynamic Line Adjustment: Enabled
Sync: 18721 Kbps ds 789 Kbps us
Asus2:
UPBO: Enabled / Stability Adjustment (VDSL): 5dB / Dynamic Line Adjustment: Enabled
Sync: 18987 Kbps ds 773 Kbps us
Asus3:
UPBO: enabled / Stability Adjustment (VDSL): Disabled (5.5dB) / Dynamic Line Adjustment: Enabled
Sync: 17866 Kbps ds 765 Kbps us
Asus4:
UPBO: Enabled / Stability Adjustment (VDSL): 9dB / Dynamic Line Adjustment: Enabled
Sync: 15362 Kbps ds 733 Kbps us
Asus5:
UPBO: Enabled / Stability Adjuctment (VDSL): Disabled (5.9dB) / Dynamic Line Adjustment: Disabled
Sync: 16402 Kbps ds 867 Kbps us
This setting (I assume "Dynamic Line Adjustment: Disabled) resulted in a very high interleaved mode on the ds and interleaved being added to the upstream.
Asus6:
UPBO: Enabled /Stability Adjustment (VDSL): Disabled (5.9dB) / Dynamic Line Adjustment: Enabled
Sync: 16575 Kbps ds 902 Kbps us
Other stuff:
If I enabled "G.INP (G.998.4) then the router failed to connect to my ECI cabinet.
If I enabled Annex mode "B" the router failed to connect.
My conclusion:
The UPBO setting has no affect.
The Stability Adjustment (VDSL) setting does actually change the downstream noise margin for the connection.
The ds sync from the Asus was much worse them that obtained from my Zyxel VMG8924 ( typically 24Mbps ds 0.6 us)
A couple of days after moving back to my ZyXEL VMG8924, interleaving has now been removed from us but it's still at a high level for ds.
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Sorry only allowed to post 3 attachments, am I allowed to post the other 3 screen shots in a second post?