@svemmy Annex B identifies ADSL over ISDN. TD-W9970 is DSL modem router which runs ADSL over POTS (Annex A). Here's the different options that you have in its WebGUI for changing this setting:

@JML67 In this post you can find the link to the FW release you're asking for.

@vikrams It's not possible to use a FW release for a different HW version device to upgrade yours: Here's how to recognize which HW vesrion you should choose when you upgrading/downgrading your...

@Szymosa If everything's OK then do nothing. If the issue persists then you can try the following: I haven't seen the VR1600v WegGUI (the screenshot is from VR2800) but most probably you should have...

@AdrianAbela Try the following: Update the WA850RE to the TL-WA850RE(EU)_V7_1.0.20 Build 250808 from here and test. If everything's OK then stay on that FW version. If the issue persists then you...

@Fredx_xda If you suspect the culprit is the new FW release then you can downgrade the FW to the previous release from here and then test the stability of your local network. The downgrade procedure...