[CentOS] NIC traffic monitoring, recording and reporting software?

I have a remote CentOS-5.3 installation that shares traffic with
another enterprise.  I want to record and measure the actual network
traffic that comes into and goes out of that host's net i/f on a
monthly basis for billing verification purposes.  Does CentOS have a
software package to accomplish this?

I have run across references to a package called vnstat as a
possible answer to my requirements, but I cannot seem to locate a
CentOS rpm package for it.

Regards,

-- 
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James B. Byrne                mailto:ByrneJB at Harte-Lyne.ca
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