G.INP: How do I get this back?

Just recently I made a request to my ISP for a minor upgrade in my VDSL upstream speed for my broadband account. This has been duly done via BT Wh but unfortunately it's changed my Interleave Depth on downstream from 16 to 1, has returned the SNR on downstream from 8.9dB to 6.8dB, and has also put the upstream SNR into the same default 6dB region. The result has been that downstream connectivity has become unstable. In particular, I can no longer stream any audio or video for more than a couple of minutes at a time before the stream's lost. The connection with the DLM remains up, however; the line doesn't drop.

What I've also noticed from my router's stats is that the INP value has been put back to 0. This, along with the Int Depth, is unrealistic for my particular copper loop, which is some 700m long and, being in a densely residential area, is subject to a fair amount of noise and crosstalk. Previously, INP had been a value of 48, and streaming had been rock solid.

The question is: how do I get a sensible INP figure back, for my connection? Do I just have to wait and hope that the DLM at the exchange will in due course automatically raise the INP figure, along with the Int Depth and the two SNRs (and probably with a small diminution of speed), or is this a case where the matter needs reporting to my ISP and them getting BT Wh to manually intervene?

If you changed from a 40/2 to a 40/10 Openreach product then DLM is automatically reset.

As G.INP was active previously it is highly likely it will re-activate in 2-3 days and restore your previous downstream stats.

There is nothing you can do to influence this except leave well alone. Do not start doing re-syncs or power cycles.

If you already have done, it may take a bit longer for DLM to reactivate as you may have made it think there is more instability than there is.

Incidentally FTTC DLM operates at cabinet level, which is where the DSLAM is, not at exchange level.

Thanks RobertoS, that's reassured me. Just a matter of me waiting and monitoring, then.

Incidentally FTTC DLM operates at cabinet level, which is where the DSLAM is, not at exchange level.

Yes, of course, you're quite right. Was still thinking in ADSL terms.

I had banding on my line for a long time, with G.INP also active. When the DLM was reset to remove the banding this is what happened.