Tinuva ... that DSL version that you are referring to is the revision of the low level firmware running in the DSP (Digital Signal Processor) part of your router system that handles the very low level ADSL communications to the DSLAM in the exchange.
Has nothing to do with Telkom.
That is loaded as part of your router firmware.
Are you saying telkom doesnt run firmware on their equipment, and that they cannot upgrade it to a newer version which works better?
Look. I had firmware 1.01 on, now 1.03 with which my modem atleast syncs again with. If telkom didnt upgrade anything, 1.01 should've still worked (but why didnt it?)
Now every technology has standards, and revision upgrades on top of current standards. A simply example:
802.11 = Wireless NIC standard...
802.11a = 11mbit in 5ghz range (i think)
802.11a = 11mbit in 2.5ghz range (once again i think, but i couldve mixed it up)
802.11g = 54mbit again in 2.5ghz range
That is just an example of how wireless revisions came out on 1 standard.
Now Telkom is running the Y-version adsl whether that is on the dslam or bras doesnt matter, the client need a modem which can understand this "language" their equipment use. If they upgraded it, most/some client will probably need to upgrade as well if their equipment dont understand the newer version or has something in thats incompatible with the new version.
It is just like k56flex doesnt understand v90 without an upgrade (56k modems)