Need help in writing a radius client

Hi, I am planning to write an ISP billing server and gateway which communicates with a RADIUS server for AAA work. Can anybody please help me with the following: 1. I need an open source library for client. I found radiusclient-ng. Is it sufficient for work. 2. Can anybody please help me find some better documentation for working me with the library, i.e. details regarding its API, cause the docs provided with the library are minimal? 3. Can I get some sample code for client anywhere? Thanks in advance Abhinay