Section: 11.2.2 Access to networks handling Non-IP data services through Packet Domain
Content: The support of Non-IP data is part of the CIoT EPS optimisations (see 3GPP TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [77]) and 3GPP TS 23.060[ General Packet Radio Service (GPRS); Service description; Stage 2 ]  [3]). A PDN/PDP Type "Non-IP" is used for Non-IP data. The Non-IP data delivery to the network handling Non-IP data services is accomplished by one of two mechanisms: - Delivery using SCEF - Delivery using a Point-to-Point (PtP) SGi tunnel Data delivery using SCEF is further described in 3GPP TS 29.128[ Mobility Management Entity (MME) and Serving GPRS Support Node (SGSN) interfaces for interworking with packet data networks and applications ]  [110]. In order to allow Non-IP delivery data using SGi PtP tunnelling based on UDP/IP (see subclause 11.8), the Packet Domain may offer direct transparent access to the Non-IP Packet Data Network with the following characteristics: - The IPv4 address and/or IPv6 prefix is assigned as part of the PDN connection establishment and identifies the PDN connection of the UE within the PLMN domain. - IP address allocation procedures for the UE (i.e. PDN connection) are performed by the GGSN/P-GW based on APN configuration. Only a single IP address is used (i.e. either IPv4 or IPv6 prefix+Interface Identifier is allocated/assigned). In case of IPv6 the GGSN/P-GW assigns an Interface Identifier for the PDN connection. The IP address or IP prefix is not provided to the UE (i.e. SLAAC / Router Advertisements are not performed. DHCP or DHCPv6 are not used). - The assigned IPv4 address or IPv6 prefix is used for UDP/IP encapsulation for PtP tunneling between the Non-IP network and the GGSN/P-GW (see subclause 11.8). - Stateless Address Autoconfiguration does not apply for IPv6. Both IPv4 and IPv6 addresses belong to the operator addressing space. User authentication and encryption of user data when accessing networks handling Non-IP data services is outside 3GPP specification.