4 Architecture considerations
32.2543GPPCharging managementExposure function Northbound Application Program Interfaces (APIs) chargingRelease 17Telecommunication managementTS
4.1 High-level Service Exposure Function architecture
The overall architecture and detailed description for Service Capability Exposure which enables the 3GPP network to securely expose its services and capabilities provided by 3GPP network interfaces to external 3rd party service provider applications are defined in 3GPP TS 23.682 [243], and figure 4.1.1 is highlighting T8 involved for interworking between SCEF and SCS/AS.
Figure 4.1.1: Northbound API of 3GPP Architecture Service Capability Exposure
4.2 Northbound API offline charging architecture
As described in TS 32.240 [1], the CTF (an integrated component in each charging relevant NE) generates charging events and forwards them to the CDF. The CDF, in turn, generates CDRs which are then transferred to the CGF.
Finally, the CGF creates CDR files and forwards them to the BD.
For offline charging, SCEF functioning as the CTF, may generate accounting metrics sets for Northbound Application Program Interfaces (APIs) CDRs:
– the SCEF, to record Application Program Interfaces transaction.
If the SCEF generating the charging information has an integrated CDF, then the SCEF can produce CDRs. The CGF may also be integrated in the SCEF, or it may exist as a physically separate entity.
If the CGF is external to the SCEF /CDF, then the SCEF/CDF forwards the CDRs to the CGF across the Ga interface. If the CDF is external to the SCEF, the charging events are transferred from the SCEF to the CDF via the Rf interface specified in TS 32.299 [50].
When an external CGF is used, this CGF may also be used by other. It should be noted that the CGF may also be an integrated component of the BD – in this case, the Bea interface does not exist and is replaced by a proprietary solution internal to the BD.
Figure 4.2.1 depicts the architectural options described above.
Figure 4.2.1: Northbound API offline charging architecture
It is mandatory to support at least one of the Rf, Ga or Bea interfaces from the SCEF as described in the present document.
4.3 Northbound API online charging architecture
Northbound API online charging is based on SCEF utilizing Ro interface and application towards the OCS as specified in TS 32.299 [50]. The Ro reference point covers all online charging functionality required for SCEF.
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Figure 4.3.1: Northbound API online charging architecture
Details on the interfaces and functions can be found in TS 32.240 [1] for the general architecture components,
TS 32.296 [53] for the OCS, and TS 32.299 [50] for the Ro application.
4.4 Northbound API converged charging architecture
The architectural options for Northbound API converged charging are depicted in figure 4.4.1 in service-based representation:
Figure 4.4.1: Northbound API converged charging architecture
Architectural options of figure 4.4.1 apply to any Northbound API converged charging architecture of this clause.
Details on the interfaces and functions can be found in TS 32.240 [1] for the general architecture components, Ga is described in clause 5.2.4 and Bea in clause 5.2.5 of this document, and Nchf is described in TS 32.290 [57].
Figure 4.4.2 depicts the Northbound API converged charging architecture for non-roaming in reference point representation:
Figure 4.4.2: Northbound API converged charging architecture non-roaming reference point representation