Fibre BB Noise Margin query

[#1]

Having recently changed over from Unlimited Broadband (ADSL 2+) to Unlimited Fibre I'm trying to get to know the ropes with fibre BB.

I'm familiar with the usual SNRM values from ADSL 2+, nominally 6dB for download - though I was usually on a higher value than this with a banded line. Now on fibre 10/40 Mbps my Plusnet Hub 2 is reporting noise margins as 14.1/15.0 for Up/Down.

Can someone confirm these are the pretty usual default values?

TIA

[#2]

@pvmb If your modem/router is syncing at the full 40/10 speeds then you have higher margins because you have margin to spare and could sync at much higher speeds before the margins drop to the usual 6dB default level. If your speeds are not 40/10 then something is wrong.

[#3]

...OK, thanks RealAleMadrid. That is more or less what I expected.

Actually I am rather surprised by this, I expected a little bit of a possible issue with FTTC with my current setup.

I don't operate from the incoming BT/Openreach 5C master socket, I use an old LJ type extension socket for the router, as I did for ADSL. It's 'worse' than that! The extension socket is also a "master" socket (historical reasons) - so I have two master sockets in parallel. More, the LJ extension master socket is old style with all the original components, including the surge suppressor, in place.

Previously I was given to understand the suppressor component, while not a problem with ADSL, would impact the higher range of frequencies used by fibre. So I was expecting to have to move initially from the extension socket to the 'true' master socket to get full fibre speed and later try modifying the extension socket - removing the surge suppressor - to get max speed on the extension.

But in practice this has proved to be unnecessary, the existing extension socket is working fine.