my provider (easybell (Telekom reseller)) recently switched from an old VDSL2 DSL-AccessMultiplexer (50/10 Mbit/s) to the brand new ADSL SuperVectoring boards that enables 250/40Mbit/s.
Before the change my TP-Link TD-W8970B connected just fine with always the maximum booked speed of 50/10Mbit/s.
However after the change the maximum sync that is possible is now 20/1.5Mbit/s.
I read a lot about this problem and it seems to be a default fall back profile for 30a enabled line cards. So DSL modems that don't support vectoring will be downgraded to this profile to prevent interference with all the other vectoring enabled modems that are connected to the same cable harness.
I'm awear that the default firmware of the TD-W8970B that comes with the stock LEDE doesn't support VDSL Vectoring aka G.993.5. So I tried to get one of these here working: https://xdarklight.github.io/lantiq-xdsl-firmware-info/
I tried the Speedport and the FritzBox based dsl firmware blobs but none of these enabled the Vetoring functionality even though they were listed as "incl. vectoring support".
Does somebody tested this in germany on a Telekom DSL-AccessMultiplexer?
Maybe I just had bad luck. Which blob shall I use?