I think we're just talking circles. The One Ring is a more integrated DialCentral equivalent. It lets me make calls via Google Voice and send/receive SMS as well. At any rate (to keep somewhat on topic) it is written in python. After a couple of quick google searches, it appears to me that while python supports ipv6, it must be explicitly setup. So most python apps wouldn't necessarily work with ipv6 unless the author intends them to. I'll guess it's possible for The One Ring to work with ipv6, if the maintainer adds the necessary python code/support. Don't know how easy that will work out to be though.