OpenEPC includes a streamlined, yet comprehensive Offline Charging System (OFCS). This is composed of the following functions and components:

  • Policy and Charging Enforcement Function (PCEF), modularly integrated with the PGW functionality
  • Charging Data Function (CDF)
  • Charging Gateway Function (CGF)
  • Billing Function (BF) with an included Web-based GUI for displaying simple, consolidated priced bills
The Gz interface between PCEF and OFCS is implemented in the Diameter option as Rf. The CDR passing interface between the CDF, CGF and BF are simplified. The CDR storage can currently use databases or files, with the added capability of importing CDRs from external components over, for example, FTP.

The CDR format follows the 3GPP standards, both in encoding, as well as in the file format storage. Additional formats and encodings can be implemented on-demand.

Under development or evaluation are also the Gy interface between the PCEF and the OCS in the Diameter option as Ro, as well as the Ga interface with GTP’ for exchanging CDRs.

The functionality provided is also integrated with the OpenIMSCore project, providing correlation capabilities between EPC and IMS architectures.