About OCS Testing


In a OCS (Online Charging System) Node test case, Landslide emulates the OCS (Online Charging System) on the LTE network. The Ro reference point provides interface to Packet Data Network Gateway (PDN GW) SUT.  

Online charging is a process where charging information for network resource usage is collected concurrently with the resource usage as in the offline charging service. However, authorization for the network resource usage is obtained by the network before using the actual resources. This authorization is granted by the Online Charging System when a request is received from the network.

When receiving a network resource usage request, the network assembles the relevant charging information and sends a charging occurrence to the OCS in real-time. The OCS then returns an appropriate resource usage authorization. The resource usage authorization may be limited in its scope (for example, volume of data or duration), therefore the authorization may have to be renewed from time to time as long as the user’s network resource usage persists.

That is, online charging is a mechanism where charging information can affect, in real-time, the service rendered and therefore a direct interaction of the charging mechanism with the control of network resource usage is required.

NOTES:
  • The charging events for online charging are transferred to the OCS using the Ro reference points.
  • The OCS emulator includes ABMF (Account Balance Management Function) and RF (Rate Function).

Online charging for both events and sessions between CTF and the OCF is performed using the Ro reference point. The Ro reference point supports integrity protection and authentication when the CTF is outside the operator domain.

 

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

    • Real-time transactions;
    • Stateless mode (Event Based Charging”) and stateful mode (Session Based Charging) of operation;
    • Provides its own reliability mechanisms, e.g. retransmission of charging events, to run also on unreliable transport.

In addition, the protocol supports changeover to a secondary destination (alternate OCS) in case of the primary OCF not being reachable.

Charging Trigger Function

Online charging is a process where charging information is collected in the network element in the same fashion as in offline charging. This implies that, from the functional perspective, the CTF creates the charging events used for online charging. While the accounting metrics used in online charging are generally the same as in offline charging (i.e. the charging mechanism is transparent to the Accounting Metrics Collection), the following functional enhancements concerning the Accounting Data Forwarding are supported in the CTF for online charging:

Rating Function (RF)

The Rating Function (RF) determines the value of the network resource usage (the charging event received by the OCF from the network) on behalf of the OCF. The OCF furnishes the necessary information, obtained from the charging event, to the RF (Rating Function) and receives in return the rating output (monetary or non-monetary units), via the Re reference point. The RF may handle a wide variety of ratable instances, such as:

Online Charging Function

The Online Charging Function (OCF) consists of three distinct modules, namely the Immediate Event Charging (IEC), the Session Based Charging Function (SBCF) and the Event Based Charging Function (EBCF).

OCS Node Testing

The OCS server provides online charging and Credit Control services for a SUT. Add the OCS Node test case to a test session and configure the SUT to direct OCS traffic to the server's IP address.

The test case can emulate two servers, one primary and one secondary, for failover testing and can generate messages as though they were routed by a Diameter proxy, eliminating the need for physical proxy servers.

IMPORTANT: If an OCS 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 since the test server must allocate resources for the Mobile Subscriber sessions and simultaneous online-charging stateful sessions established per Subscriber.

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

With each test case, you define:

NOTE: The maximum number of mobile subscriber accounts and maximum number of sessions per subscriber supported is determined by your license capacity.

Measurements

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