I did say the telnet commands are different. DMT has several versions of the commands within each DMT version.
I'm sure a year or so ago we got someone to manage it. IIRC the 834Gv3 is one that uses the cat series, though it might have been the adsl ones.
I'd like to see where kitz says DMT doesn't work. The OP can clearly telnet in, so maybe he can tell us a sample command that works.