 IPv4 address. The message also contains PDN Type information element requesting the PDN Type Deploying IPv6 in 3GPP Networks Attach Request/PDN Connectivity Request PDN Type IPv4v6, PCOs Location Update - download the subscription profile default APN, provisioned PDN Type IPv4v6, possible static address info, Create Session Request PDN Type IPv4v6, APN xyz, PCOs, static address info, if available, Check PDP Type, assign IPv4 address and IPv6 /64 prefix, generate IID for the UE and the PGW, Possibly visit external servers in a PDN AAA or DHCP for address management and authorization. PGW configures its link-local address. Create Session Response IPv6 prefix, IID, IPv4 address, PDN Type IPv4v6, PCOs, Attach Accept/Activate Default EPS Bearer Context Request IPv6 IID, IPv4 address, PDN Type IPv4v6, PCOs, UE configures IPv4 address and IPv6 link-local addresses using the IID received from the network IP connectivity set up RA with PIO (assigned /64 prefix, L=0, A=1), M=0, O=0/1, MTU option, etc Figure 4.27 Simplified initial E-UTRAN attach example including IPv4 and IPv6 address configuration. IPv4v6. The UE may also request a specific APN, but usually during the initial attach that is not done and the network defined default APN will be used for the PDN Connection. 2. The MME downloads the subscriber subscription profile from the HSS. The profile contains information such as the default APN, the subscribed APNs for the subscrip- tion along with the PDN Types for each APN. It is also possible that some APN is provisioned with static IPv4 address and/or IPv6 prefix, and if this is the case the static addressing information would be used during the subsequent Create Session Request messages for the PDN Connection activation. 3. The MME sends the Create Session Request GTP Control Plane version 2 (GTPv2-C) message over the S11-interface to the SGW, which further sends the corresponding Create Session Request message over the S5/S8-interface to the PGW. At this point, the MME also checks for the possible fallback cases 