Right now RUT950 will not be capable of sustaining IPv6 connection that you're hoping for. It will gain IPv6 address from the other end, but services and some basic functions still do not fully support it.
What I could suggest is looking at the possibility to upgrade. RUTX devices are also not fully done with IPv6 corrections, but they are much more stable with it and almost all of the functions should work properly.
Of course, RUT9XX series devices will not be left behind, they're awaiting firmware updates that should overhaul their structure and functionality soon.