Section: 5.2.6.12 Nnef_APISupportCapability service 5.2.6.12.1 General
Content: In order to support interworking with EPC, the NEF is integrated with SCEF as a combined SCEF+NEF node for network exposure as defined in clause 5.17.5 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2]. The common services provided by SCEF+NEF may become unavailable because the UE is now being served by a node (e.g. MME) or NF (e.g. AMF) that does not support that service. If the availability or expected level of support of a service API associated with a UE changes, for example due to a mobility between 5GC and EPC, the AF can be made aware of the change via this service. This service consists of Subscribe, Unsubscribe, Notify service operations. It supports informing AF of the availability or expected level of support of a given service via a response to the One-time report type subscribe request of the AF or via a notification to the Continuous report type subscription of the AF.