aram- eters need to be supported by protocols that are commonly implemented in wireless modems, such as SNDCP and PDCP. If a modem does not support the set up of the IPv6 type of PDN Connection, a UE is not going to be able to set up a native IPv6 3GPP connection. Some modems supported IPv6 PDP Context type from early 2000, but most did not for the first decade of this millennium. However, at the time of writing, IPv6 support seems to be making its way to all significant chipsets, and hence the IPv6 bottleneck cannot be considered to be on modern modems. 4.7.2 Required RFCs for Host UEs The set of required RFCs naturally depends on supported IPv6 features. The minimal set of RFCs that are needed on 3GPP UEs is listed in Table 4.10. RFCs that are optionally needed are listed in Table 4.11. Informational documents that may help build protocol and node implementations are listed in Table 4.12. Out of the listed informational documents those related to IPv6 API are particularly interesting, as they describe the basic model of how applications may be utilizing IPv6. The API RFCs are informational in nature, as the APIs are always internal to an operating system, fully dependent on the operating system's architecture, and invisible outside of a node. It is certainly possible that a UE is also attaching to non-3GPP networks, in which case additional requirements, or priorities, may be in place. For example, while stateful DHCPv6 is not mandatory in 3GPP networks, in corporate WLAN networks it typically is. This requirement list also does not cover IPv6-related RFCs that might be required for additional non-3GPP related features. Therefore, for example, IPsec, application spe- cific multicast use, numerous DHCPv6 options, MIPv6, or other than WLAN access type related RFCs are not listed even if they generally are optional for every imple- mentation. We have also not included any of the IPv6 transition mechanisms in the lists we have on this section, as the basic IPv6 transition tools used in 3GPP accesses, and described 