iPhone 2G was released when 3G networks were becoming common among better telcos. For critical period in the early 3GPP network stack, it was niche player. How

iPhone 2G was released when 3G networks were becoming common among better telcos. For critical period in the early 3GPP network stack, it was niche player. However, Mobile networks are actually biggest users of IPv6, especially if the rumour I heard about licensing being cheaper on IPv6 is true (IPv6 is also in many ways cheaper on backbone implementation). This is why Apple recommends IPv6 accessible sites, because for many mobile networks IPv6 is faster - it avoids multiple levels of network address translation through possibly limited number of gateways. The mobile stack itself doesn't really care for IPv4 vs IPv6 except for v6 making it much easier to build the network and having easier IP Mobility (keeping connections across moving addresses). Protocols run perfectly well on both v4 and v6 (SIP, IPsec, various other L4 and higher protocols involved)