This Annex provides the information about the role of CAPIF in charging service API invocations. The common architecture for charging is illustrated in clause 4 of TS 32.240. There are two charging mechanisms - offline charging and online charging. The role of CAPIF in both these charging mechanims is illustrated for informational purpose in this subclause. The API invocations are subjected to charging (online, offline) as illustrated in Figure C.1-1.

The API invocations are subjected to online charging as illustrated in Figure C.1-1. The API exposing function provides the API invocation charging information to the CAPIF core function. The CAPIF core function further interacts with an online charging system in real-time by providing the charging information and further the CAPIF core function receives the authorization corresponding to the charging information.

The API invocations are subjected to offline charging as illustrated in Figure C.1-1. The API exposing function provides the API invocation charging information to the CAPIF core function. The CAPIF core function provides the charging information to the offline charging system. The offline charging system generates the CDRs for the API invocation and further transfers the CDR files to the billing domain.