I had the same difficulty when I was the brief owner of two Vigor 130 devices and found the following explanation on the (login required) DrayTek web site.
Thank you for posting that Draytek explanation. I still find it difficult to understand exactly what is meant.
Starting from first principles, "ATU-C" refers to "ADSL Transceiver Unit, Central Office", i.e. the DSLAM or MSAN and "ATU-C" refers to "ADSL Transceiver Unit, Remote Site", i.e. the local modem/router. Nowadays most references are to "xTU-C" and "xTU-R", allowing for the presence of G.993.2 (i.e. VDSL2).
However Draytek devices will report --
> vdsl status more
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Near End Far End Note
Trellis : <blah, blah>
Notice the heading, "ATU-R Info (hw: annex A, f/w: annex A/B/C)", is explicitly stating "ATU-R" i.e. the local modem/router. Under that main heading there are two column headings, "Near End" and "Far End". Logically, something has to be incorrect about what is displayed.
To me, the main heading "ATU-R Info (hw: annex A, f/w: annex A/B/C)" needs to be removed and the column headers, "Near End" & "Far End" should be changed to read "US" & "DS", respectively.
I also see that the second half of my last sentence is in alignment with what ejs