All Apple devices and iPhone apps are mandated to work on these networks, or you don't get into the app store. This is because many mobile networks are IPv6-onl

All Apple devices and iPhone apps are mandated to work on these networks, or you don't get into the app store. This is because many mobile networks are IPv6-only. IPv4-only servers are accessed through a separate gateway server provided by the network operator, with a 10-20% latency penalty, and limited throughput.