The number of cell phones in use and the number of IPv4 addresses, 4,294,967,296, will probably intersect this year. With next generation, 4G, cell phones being all IP, will this force the adoption of IPv6? Not necessarily.Cell phone carriers will use IPv6 in their 4G backbone networks, but whether the cell phones themselves will have IPv4 or IPv6 addresses is still TBD. Either way, with NAT/PAT technologies, IPv4 networks and devices can coexist. Since a call may go to another cell carrier, a traditional phone carrier, an enterprise, or another VoIP service, some IPv6-to-IPv4 interworking will need to occur.
So what features or functionality will be lost in the translation? None that I am aware of. IPv6 adds significant address space, but not a "killer app" for end users/consumers. Fixed Mobile Convergence (FMC) has the potential to lower usage costs and add local system integration. But changing IP addresses, once a communication session has been established, has security, reporting, roaming, and operational challenges, especially if it is IPv6 to IPv4.
Most enterprises should keep IPv6 on their 3-5 year radar. 4G, IPv6, cell phones, though, do not appear to be the "killer app" for IPv6 at this point.
