I just have G,DMT ticked.
If I have both G.DMT and ADSL2 ticked then the router will sync using ADSL2. Also if I have G.DMT, ADSL2 and ADSL2+ ticked then the router will use the ADSL2+ modulation.
Previously instead of increasing the SNRM values with ADSL2+, due to high error rates, I chose to use ADSL2 with a forced downstream SNRM of 3dB (upstream remained at the default 9dB) and got a sync rate only slightly slower than ADSL2+ with a SNRM of 6dB. This I did in agreement with my ISP nearly one year ago.
However instability began just before Xmas so I reset the downstream ADSL2 SNRM to 6dB but unfortunately there was no improvement. Now I'm using the G.DMT setting with a downstream SNRM of 6dB and the line is performing really well
Edit: looks like you are syncing with interleaved ADSL1 when using the 7800N's G.DMT setting.
Edited by 4M2 (Mon 22-Jan-18 16:36:31)