User Data Transfer

[Sumith Ail]

Hello   Since we are a hosting company, we would provide our customers to an amount of data transfer per month, which would include there web, mail and ftp traffic.   Can anyone guide me to a solution for this. I understand that we would require to analyse the log files for a domain wise results. But is there a single solution for this   We are using Apache, Qmail, Vpopmail, Proftpd, on RH linux 6.2 server.   Thanks in advance.   Regards Sumith