Verizon Wireless assigns you ONE IPv4 address and ONE /64 IPv6 prefix for their cellular service, and VZW would reset your datalink once they received 1 packet with an illegal source address.
We have NAT for IP but for IPv6 we would like to avoid address translation to get some kind of end-to-end communication.
NPTv6, defined in RFC6296, would help us to do stateless prefix translation for IPv6.