ASUS DSL-AC68U
Not sure about yourself but when using the Asus my Max Attainable Rate was always an average of 10-20 mbps higher than when using a Broadcomm or Lantiq (ECI) Modem. I'm wondering if its this that is causing the instability for most people as the line is trying to sync far higher than is what's stable, thus causing re-trains when the line becomes unstable.
I never bothered to put the unlocked firmware on my BT OR modem, so I don't have much idea of the connection stats. I did regularly speed test my connection and it was a solid 37M/6.5M for years. My ping times were always quite high though (around 40ms), which I now know is indicative of a high level of interleaving.
I'm on the old infinity 1 plan so my speed is limited to 39M/10M anyway. The ASUS is currently giving me a significantly higher upload speed than the BT OR modem (around 8 to 9M), but my download speed has been hammered by DLM
so it's only 22M at the mo.
I did experiment with turning down the TX power to try to get the upload speed near to the speed achieved by the BT OR modem. Initially this did seem to work, but after DLM increased my download speeds back to normal again, my line stability went bad and speeds were reduced to where they are now.
One weird thing I did notice when experimenting with the TX power was interplay between the UPBO setting and the TX power. With UPBO disabled, turning down the TX power had very little impact on the connection speed (speed stayed near my max rate of 9M)...but when I reduced the TX power to -5dB, it refused to connect at all.
With UPBO enabled, reducing the TX power did actually change my upload connection speed....a setting of -4dB reduced my TX connection down to less than 6M. I guess it could be that TX power reduction just doesn't work with UPBO disabled, but that seems to be a bit counter to the purpose of those controls? Also that wouldn't explain why I couldn't connect when I reduced the TX power by 5dBs....it must have been doing something to the TX signal??
I have started to wonder if the main problem with the ASUS modem is that it's not controlling the TX power and connection speeds properly or it's not dealing with UPBO commands correctly. In my case it could explain why there is such a big disparity between the speed that the ASUS connects at and the speed that the BT OR modem connected at. Having said that, it could also be explained by the BT OR modem being crap at upstream connections....it's just the BT OR modem is stable and the ASUS Mediatek Modem is a POS.
I guess my real worry is that the Mediatek chip is just fundamentally rubbish and no amount of firmware tweaking will fix it. I have no technical basis for that supposition, I just have a bit of bad history with Mediatek so I don't really trust them.
Anyway, I'll give the new firmware a go this evening....I guess the worst that can happen is that the update bricks it. At least then I'd be on solid ground asking for a refund