Section: 5.10 Multiple-PDN support and PDN activation for UEs supporting "Attach without PDN connectivity" 5.10.1 General
Content: The EPS shall support simultaneous exchange of traffic to multiple PDNs through the use of separate PDN GWs or a single PDN GW. The usage of multiple PDNs is controlled by network policies and defined in the user subscription EPS Optimisation. The EPS shall support UE-initiated connectivity establishment in order to allow multiple PDN connections to one or more PDNs. It shall be possible for a UE to initiate disconnection from any PDN. All simultaneously active PDN connections of a UE that are associated with the same APN shall be provided by the same PDN-GW. UE support for multiple PDN connections is optional. If the Control Plane CIoT EPS Optimisation is supported: - a PDN connection of Non-IP PDN Type may also be served by an SCEF (see TS 23.682[ Architecture enhancements to facilitate communications with packet data networks and applications ]  [74]); multiple PDN connections of Non-IP PDN Type may be served by the same or multiple SCEFs; and - the MME decides, based on APN Configuration information, whether a PDN connection is served by an SCEF or a PDN GW.