Open source PCRF, PCRF experience and PCRF implementation

What is PCRF?

PCRF is a network entity in the policy and billing control (PCC) subsystem of the LTE network EPC subsystem. Specification documents for LTE networks or EPC networks can be found on the official website of 3GPP, FTP. The PCC-related specifications are:

3GPP TS 23.203; 3GPP ts 29.208-3GPP ts 29.219.

Simply put, PCRF is using the diameter protocol to obtain relevant information from the OCS via the RX interface from the Spr,sy interface, using this information to develop a policy-related billing rule. These rules are then provided to the PCEF through the GX (other interfaces, which are not covered in the implementation, and are not mentioned at this stage).

Diameter protocol Implementation

The diameter protocol stack is a required component to implement PCRF. There are many openimscore in the open-source diameter protocol stack that contain the C language version of the Cdiameter protocol stack and the Java version of the Jdiameter protocol stack. Openimscore is an experimental version of CSCF and HSS in an IMS system in LTE networks, and can be referenced by relevant design and as a development test tool. function descriptions such as:

The Open source project's website provides detailed design documentation and use of hands. The selfless dedication to open source and provide detailed documentation pays tribute. In addition, Trillium & CCPU (continuous Computing), the commercial Diameter,sip and other LTE-related protocols, compared to open-source protocol, provides more granular functionality, better packaging and performance. The diameter Dictionary provided by developing Solutions official website is a convenient and beautiful resource for the diameter interface associated with the implementation of the diameter in LTE networks.

Open-Source PCRF

People are used to referencing existing experiences before they do something. Newton said: Stand on the shoulders of giants. Implementing software, borrowing or trimming existing "wheels" is not a quick tool. Limited by capacity, the real open source PCRF can be found, and the UCT PCF is implemented by Java in the University of Cape Town, South Africa. This version simply implements the policy control function. Its diameter protocol uses the Java version of the Openimscore, and its test platform is built with the Openimscore system. The software is a long time and extremely difficult to find.  Recent downloads are available in the CDSN resource library. A range of commercial LTE networks, such as Openepc,open5gcore, are derived based on Openimscore. They are all from the same organization: FOKUS.

Fully functional PCRF Experience edition

FREEPCRF, official website. Don't be deceived by this name. The free here is not open source, but the company offers a PCRF version that can be experienced. Available using VM image mode. 

Select the properties of the image file to download and use the experience once it is started. The website provides a detailed and almost elegant documentation, if you have questions, you can go to the Forum on the official website to find or consult. I will be a separate article, recording FREEPCRF installation and experience experiences . The software provides a commercial version.

PCRF implementation

In order to achieve PCRF, the following preparations were made:

1, reading Research 3GPP related specification document TS 29.207-29.219; PCRF to achieve the requirements;

2, reference the domestic operators of some technical specifications of the document, compared with the 3GPP specification document content;

3. Read the diameter RFC documentation and refer to the open source diameter and commercial diameter documents. Crop and enhance the diameter protocol stack

4, the trial experience of the FREEPCRF software, detailed study of related functions. and carefully contrast it into the PCRF system solution and design documentation.

5, using C + + coding to achieve related functions

6, using Seagull traffic simulator and SIPP test tool to do PCRF bench test

7, docking internal PCEF and IMS and OCS network element, verify PCRF function and performance

8, A separate article summarizes the implementation details

Open source PCRF, PCRF experience and PCRF implementation