Thank you @David-TP, your help is much appreciated.

Are you sure that it won't make much difference? Because if you look at the at the schematics, the wiring is different. Unless the DSL signal is only transmitted through the 1a and 2b pins on the TAE side and pins 5 and 2 respectively on the RJ11 side, which would come out as the same from what I understand.

To add to the confusion, on the internet you will information like this:

As a rule, all newer devices (import devices, but also newer devices from German manufacturers such as Siemens, T-Com, etc.) are equipped with TAE-F connection cables according to the US standard. Older devices (older Telekom or older Siemens phones) require a TAE-F connection cable according to the German standard. This distinction is to be seen as a "rule of thumb". There can also be exceptions here.

I believe the US standard here is the same as the international or universal standard. So I think I will just go with a international / universal cable and let you know whether it works or not when I get it.

Schematics for German standard

Schematics for universal standard

Hello,

just wanted to let you know that the international / universal cable ended up working just fine. The VR600v that I have is for the German market (comes with German manuals etc.) and it appears all newer devices for use in Germany are designed for the international / universal standard while the German standard is only used by legacy devices like old phones.

Have a nice day