Section: 13.3 PDN Interworking Model of P-GW for DHCP
Content: A DHCP Client shall be located in the P-GW used for interworking with the IP network as illustrated in Figure 16g. Figure 16g: The protocol stacks for the Sgi IP reference point for DHCP The DHCP client function in P-GW shall be used to allocate IP address(es) to the UE and/or to configure associated parameters via external DHCP servers in PDN(s). As both IPv4 and IPv6 address allocation are supported in EPS, the P-GW shall have both DHCPv4 and DHCPv6 client functions. The procedures where the DHCP client function in the P-GW is used are further described in TS 23.060[ General Packet Radio Service (GPRS); Service description; Stage 2 ]  [3], TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [77] and TS 23.402[ Architecture enhancements for non-3GPP accesses ]  [78]. The procedures are IPv4 address allocation and IPv4 parameter configuration via an external DHCPv4 server in a PDN; IPv6 Prefix allocation via stateless address autoconfiguration; and IPv6 parameter configuration via stateless DHCPv6. These procedures are detailed in the subclauses below.