Section: 4.3.17.8 Support for Non-IP Data Delivery (NIDD) 4.3.17.8.1 General
Content: The support of Non-IP data is part of the CIoT EPS Optimisations. A PDN Type "Non-IP" is used for Non-IP data. The Non-IP data delivery to SCS/AS is accomplished by one of two mechanisms: - Delivery using SCEF as defined in clause 4.3.17.8.3.2. - Delivery using a Point-to-Point (PtP) SGi tunnel as defined in clause 4.3.17.8.3.3. When the Reliable Data Service is not used, Non-IP data in-sequence delivery cannot be guaranteed and data PDUs may be lost requiring higher protocol layers to ensure guaranteed delivery when needed. The Reliable Data Service is defined in TS 23.682[ Architecture enhancements to facilitate communications with packet data networks and applications ]  [74]. NOTE: If UEs use protocols that require broadcast/multicast mechanisms (e.g. use "IP stacks" on top of PDN connections of type "Non-IP"), this may cause increased traffic and power consumption to the UE and the network. The SMS service may also be used to deliver data without use of the IP protocol. The SMS service is always supported for CIoT EPS Optimisations, i.e. can be used simultaneously with Non-IP and IP data. When only the SMS service is needed, an attach without PDN connection establishment can be used, see clause 5.3.2. Dedicated bearers are not supported for the Non-IP data.