Section: 11.2.1.3 IPv6 Non Transparent access to an Intranet or ISP
Content: When using IPv6 Address Autoconfiguration, the process of setting up the access to an Intranet or ISP involves two signalling phases. The first signalling phase is done in the control plane and consists of the PDP context activation or initial attach (e.g. create default bearer) for EPC based access, followed by a second signalling phase done in the user plane. The user plane signalling phase shall be stateless. The stateless procedure, which involves only the MS/UE and the GGSN/P-GW, is described in subclause "IPv6 Stateless Address Autoconfiguration". For APNs that are configured for IPv6 address allocation, the GGSN/P-GW shall only use the Prefix part of the IPv6 address for forwarding of mobile terminated IP packets. The size of the prefix shall be according to the maximum prefix length for a global IPv6 address as specified in the IPv6 Addressing Architecture, see RFC 4291 [82]. The GGSN/P-GW indicates to the MS/UE that Stateless Autoconfiguration shall be performed by sending Router Advertisements as described in the corresponding subclause below and according to the principles defined in RFC 4861 [89] and RFC 4862 [83]. For MS/UE having IPv6, IPv6 Stateless Address Autoconfiguration is mandatory.