shows the non-roaming architecture for Service Exposure for EPC-5GC Interworking. If the UE is capable of mobility between EPS and 5GS, the network is expected to associate the UE with an SCEF+NEF node for Service Capability Exposure.
In Figure 18.104.22.168-1, EPC Interface represents southbound interfaces between SCEF and EPC nodes e.g. the S6t interface between SCEF and HSS, the T6a interface between SCEF and MME, etc. All southbound interfaces from SCEF are defined in TS 23.682
and are not shown for the sake of simplicity.
In Figure 22.214.171.124-1
, 5GC Interface represents southbound interfaces between NEF and 5GC Network Functions e.g. N29 interface between NEF and SMF, N30 interface between NEF and PCF, etc. All southbound interfaces from NEF are not shown for the sake of simplicity.
Interaction between the SCEF and NEF within the combined SCEF+NEF is required. For example, when the SCEF+NEF supports monitoring APIs, the SCEF and NEF need to share context and state information on a UE's configured monitoring events if the UE moves between from EPC and 5GC.
The north-bound APIs which can be supported by an EPC or 5GC network are discovered by the SCEF+NEF node via the CAPIF function and/or via local configuration of the SCEF+NEF node. Different sets of APIs can be supported by the two network types.
represents the roaming architecture for Service Exposure for EPC-5GC Interworking. This architecture is applicable to both the home routed roaming and local breakout roaming.