Charging Function
CHF (Charging Function) is responsible for generating the CDR and sending it to the CGF (Charging Gateway Function). As a quota control node for online charging, CHF performs online charging for various services of users.
SMF communicates with CHF via Nchf. CHF dynamically discovers the user's home OCS based on ISUP information. CHF forwards the Nchf's charging message to the user's home OCS. CHF receives the Nchf' charging response message returned by the home OCS and sends it to the access SMF.
