bandwidth usage for billing

[sarv]

Hi everyone,
I'm new in Cacti, I want to measure bandwidth usage for billing then I must use data in rrd file and process them but I don't know to how process rrd file and where is rrd file?. I want to write a application(or web service) to pass bandwidth usage to another application.
please help me

[sarv]

Hi,
anybody don't have any idea?
Please help me , I need your advise.