In this architecture, IMS nodes, CHF, CGF and corresponding Billing domain are located in the same PLMN.
The IMS Nodes for which this architecture applies are the MRFC, IMS-GWF (connected to S-CSCF using ISC) and SIP AS, the architecture for MMTel AS is described in TS 32.275. In addition the MRFC and SIP AS may support offline only charging via Nchf interface.
The general architecture components can be found in TS 32.240.
Ga is described in clause 5.4.5 and Bi in clause 5.4.6 of the present document, and Nchf is described in TS 32.290.
Figure 4.4.2 depicts the IMS converged charging architecture in reference point representation:
The architectural options of Figure 4.4.1 apply to Figure 4.4.2 with IMS node, CHF and corresponding Billing domain/CGF located in the same PLMN.
The different IMS architectures for the support of IMS services for roaming users are specified in TS 23.228, and can be considered under two categories:
The architectural options of Figure 4.4.1 apply to Figure 4.4.3 with IMS node, CHF and corresponding Billing domain/CGF located in the HPLMN.
Figure 4.4.4 depicts the IMS converged charging architecture in reference point representation for CHF, in IMS with IMS-level roaming interfaces: