About OFCS Testing


In a OFCS (Offline Charging System) Node test case, Landslide emulates the OFCS (Offline Charging System) to provide the Rf interface to Packet Data Network Gateway (PDN GW) and the Serving Gateway (Srv GW) SUT. The Offline Charging Server processes ACR (Account Credit Request) message from  PDN GW and/or Srv GW and generates an ACA (Accounting Credit Answer) when the request is valid and user is known.

Offline charging is a process where charging information for network resource usage is collected concurrently with that resource usage. The charging information is then passed through a chain of logical charging functions. At the end of this process, CDR files are generated by the network, which are then transferred to the network operator's Billing Domain for the purpose of subscriber billing and/or inter-operator accounting (or additional functions, e.g., statistics, at the operator’s discretion). The BD typically comprises post-processing systems such as the operator's billing system or billing mediation device.

That is, offline charging is a mechanism where charging information does not affect, in real-time, the service rendered.

NOTE: The OFCS Node includes the following functions:
  • Implements the CDF (Charging Data Function) but does not create CDR (Charging Data Record).
  • Supports both event-based and session-based charging activities concurrently. The type of activity is defined by Accounting-Record-Type AVP.
  • Offline charging server processes ACR message from either PDN GW or Srv GW and generates an ACA when the request is valid and user is known.

RF Interface

The Rf reference point supports interaction between a Charging Trigger Function and a Charging Data Function. The following information flows across this reference point in real-time:

The protocol (s) crossing this reference point supports the following capabilities:

In addition, the protocol should support changeover to a secondary destination (alternate CDF(s)) in case of the primary CDF not being reachable.

Charging Trigger Function

The Charging Trigger Function (CTF) generates charging events based on the observation of network resource usage. In every network and service element that provides charging information, the CTF is the focal point for collecting the information pertaining to chargeable events within the network element, assembling this information into matching charging events, and sending these charging events towards the Charging Data Function.

Charging Data Function

The Charging Data Function (CDF) receives charging events from the Charging Trigger Function via the Rf reference point.

OFCS Node Test Case

You can use the OFCS Node test case in a test session. The OFCS server provides charging services for a SUT and responds to accounting requests, but does not maintain accounting records.

Add the OFCS Node test case to a test session and configure the SUT to direct OFCS request messages to the server's IP address. One server can service more than one SUT as long as the OFCS server's message attribute configuration will produce response messages that are valid for the SUTs. For example, to provide OFCS services, you can configure different attribute values for responses to the PDN GW and responses to the Srv GW.

IMPORTANT: If an OFCS Node test case shares the same test server as another test case the maximum activation rate and capacity of the nodal test case is reduced.

  • The maximum achievable activation rate is reduced by 10-20% depending on the application.

  • The maximum number of simultaneous sessions is reduced.

You can avoid these restrictions by running the OFCS Node test case on another test server as shown in the diagram.

With each test case, you define:

OFCS Nodal Test Case

You can use the OFCS Nodal test case in a test session. The OFCS Nodal can simulate diameter accounting request to OFCS Node based on configuration to SGW and/or to PGW. OFCS Nodal uses Diameter Protocol for Rf Interface.

Measurements

Measurements collected for the OFCS Node test case are reported on the following tabs.

NOTES:
  • Per session data is created as csv file at the end of test when relevant options are selected (Report Options>TS Generted Per MN/Session Reports).
  • One session corresponds to one APN. There will be as many sessions as the number of default bearers configured per Mobile Subscriber.