The EES may re-expose the network capabilities of the 3GPP core network to the EAS(s) as per the CAPIF architecture specified in TS 23.222.
Depending on the deployment models (centralized or distributed) employed,
the EES assumes the role of the API exposing function (may also acts as the API topology hiding entry) as described in TS 23.222; and
the EAS assumes the role of an API invoker.
If CAPIF is supported, the EAS interacts with the CAPIF core function and the EES. The EES may further interact with 3GPP northbound service API provider (e.g. SCEF/NEF/SCEF+NEF) or directly with 3GPP core network entities (e.g. PCF) to satisfy the service API invocation requests from the EASs.
The EES may expose the network capabilities of the 3GPP Core Networks to the EAS(s) by supporting the functionalities of 3GPP northbound service API provider (e.g. SCEF, NEF, SCEF+NEF).