Billable bandwidth, how are you tracking?

[Bit_Jockey]

We are using a version of RTG in a colocation environment to determine monthly usage and billable 95th percentile.  This system was put in place long ago and we are considering alternatives.  Observium and rrdtool have caught my attention as tools to look into.  From what I understand MRTG (without rrdtool as a backend) does some fancy rounding/truncation to keep the database small, which wont do for record keeping.

Can anybody discuss or recommend a method that has worked well for them?

[wintermute000]

There are commercial solutions using netflow. I can't recall the specific vendor(s) we used in my old ISP but I defo knew it used netflow. This was a ghetto solution though, most ISPs would use radius counters that derive from the user PPPoX sessions coming off the LNS.