The obsolete models were the Draytek 2750 and 2850 which used a Metanoia VDSL2 chipset, not Lantiq.
Thank you I couldnt recall the numbers, although I did say "non Lantiq and BCM chipset based modems eg". Again I cant recall model nos but iirc some of the others were MediaTech?
That sounds very unlikely to me. I thought all the logic of selecting what profile to use was done by some part of the DLM, and then the DSLAM in the cabinet simply does what it's told regarding enabling G.INP in whichever direction(s) on a particular line.
Thats the theory, but theres some oddness that goes on if the modem isnt capable of G.INP.
As it currently stands on Huawei cabs g.inp only goes on for upstream on those modems capable of doing so. Yet it can still apply g.inp and INP for those that are capable.
It wasn't until in a live situation that Openreach saw the [unexpected] effects that trying to apply g.inp to modems that couldnt do so that they changed things and came out with G.INP Mk2.
How is DLM able to totally turn off G.INP for those ASUS modems, yet within quite a short timeframe (~2 weeks) then go back to using G.INP when a modem capable of re-tx is put back on the line. If it was just DLM then you would fully expect g.inp to go back on the line immediately a compatible router is put on the line.
Right from the very start and before re-tx went live, we were told non g.inp modems would not sync, yet on the Huaweis they still did. It wasn't until they applied re-tx to the ECI's that we started seeing the non-sync and sync instability problems.
The ECI's seem less capable of handling non compliant modems. Which is why I said I wonder if this is why they totally turned off upstream g.inp for the ECIs from the very start... knowing full well that the ECI modems and HH5As wouldnt work for upstream. In theory the ECI DSLAMs should be able to handle upstream.
In theory the ECI modems should be... and are, just they never got around to updating f/w for some reason.
I think part of the problem originates from BT never enforcing any modem compatibility rules,
^This.
It also remains to be seen if they do ever take any action against those modems causing issues. So far they don't appear to have done so other than trying to find a fix at their end. Thus delaying the roll out for the rest of us.
I suspect there were probably far more modems than anticipated being non compliant. ASUS has quite a large following as do several other modem manufacturers who havent yet bothered to apply for MCT.
All the evidence suggests that it is a compatibility issue and one which has affected the ECI's far more than the Huaweis.