Both my old 7390 and new current 7490 on a Huawei cab, showed IMP as 44/41 and on/on both on download and upload. I guess it could be erroneous reporting, especially if as I understand the BT firmware doesn't take adjustment, but the Fritz! firmware still tries nonetheless. And each therefore gives its own readings.
It might possibly explain too why the reported readings are sometimes nonsense. Could it be that the Fritz! firmware is trying some adjustment, perhaps even switching on G.INP on the upload, which is rejected at the cab? But the 7390 and the 7490 then seem to respond differently, the first losing tones and the other retaining them? But for me it took until the week before last for the problem to occur on my 7390, well after when G.INP on the upload was switched off by BT, apparently. At first connection last Thursday the 7490 showed INP off on just the upload, but after a day or so it showed as switched on, where it has remained over the weekend, reboots notwithstanding. Sync speeds and both downloads
and uploads are still the historic normal for for the Fritz! (viz better than the OR modem) for my line on the 7490.
PS Perhaps some good news. A UK user on the Aussie Whirlpool forum reports that AVM have replied saying they are working on it and hope to issue a firmware update soon. Maybe they've identified the cause
Edited by deleted (Mon 16-Nov-15 13:14:34)