Hello !
I have a ready made solution for this, I can show a demo of it, too. Obvisouly, it's not based on your CDR type, of course, and it's very highly customized, as this is my main purpose, to best fit a client's needs. I'm not trying to sell a pre-packages solution, I want to talk to you, see what your CDR format is (the one I have I built a couple of years ago for a canadian company, and they have different long distance/zones and pricing grouping) and make it work. I do have different reports, history of each number/subscriber, PDF downloadable invoice built it. Anything else you might need we'll discuss and I'll implement. The whole thing is coded in PHP with Zend Framework and uses MySQL as storage engine. It's built for performance and security, mainly, it'll be able to hold million records without a problem. So please get in touch with me and let's see the details.
PS: Forgot to mention, my bid is not final, we can discuss the price of the project depending on your requirements.
Regards,
Dragos