Ok.
I'm all updated and powered the modem back up after 45mins to an hour. New stats are as follows.
Max: Upstream rate = 28386 Kbps, Downstream rate = 78204 Kbps
Bearer: 0, Upstream rate = 20000 Kbps, Downstream rate = 66999 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Downstream Upstream
Line attenuation (dB): 17.2 0.0
Signal attenuation (dB): Not monitored
Connection speed (kbps): 66999 20000
SNR margin (dB): 9.3 11.3
Power (dBm): 13.5 7.4
Interleave depth: 16 8
INP: 49.00 47.00
G.INP: Enabled
My pings have reduced back down to 25ms which is the best it has been. It normally sat around 28ms to BBC.
I wonder if I will get any further speed increases hopefully back to where I started with all my issues in January where I was synching around 75Mb.
Considering my line profile went to 60.1Mb with the ECI modem two days ago, I'm impressed so far that I've gained 6Mb in two days.
OK - you definitely have G.INP running now - those INP values above 40 are a big giveaway.
Given the change you've seen, it suggests that the very recent slowdown was probably caused by your modem not being compatible with G.INP.
Aside: I know that BT engineers have been told that ECI modems, with old firmware, will not sync at all. However, we're seeing more cases like yours - with noticeable slowdowns and big increases in latency - that happen to both Huawei and ECI modems. We know the Huawei modems that end up like this seem to be on old firmware, but we can't tell about the (locked) ECI's. I wonder if this is new behaviour from BT, as yet unreported via engineers, so that modems at least keep some form of connection up.
Your status now suggests you are syncing at the top of one of the DLM bands (I guess 67Mbps), as you have some SNR margin to spare. That 3dB of SNR would normally be worth another 11Mbps or so - which ties in with the modem's own estimate of an attainable 78Mbps.
Zen's suggestion seems fair enough for now.
