Math seems sound. 300 seconds is a function of exporter interval and collector file rotation. Most flows are shorter. Some will be longer if the exporter interval (active flow timeout) isn't configured properly.
It's safe to use 300 if you only care about aggregate flow data and the exporter config is good. But, I think it's better to use start/end time to determine each flow's length. More detail at http://wvnetflow.sourceforge.net/#key-time -Craig On Sat, 29 Jan 2011, Drew Weaver wrote: > Hey all, I wanted to see if my math makes sense for converting total traffic > amounts to bit rate using sampled netflow. > > Converting bytes (total) to bits per second (throughput) using sampled > netflow rough estimate: > > netflow sample rate: 1:500 > bytes (after sampling): 3639786 > bytes (before sampling): 500 * 3639786 = 1,819,893,000 > bits total : 1,819,893,000 * 8 = 14559144000 > bps : 14559144000 / 300 = 48530480 > 48,530,480 (48Mbps) > > formula = bytes * sample rate (500) * 8 [conversion to bits] / time of > netflow sample (300) > > This is just a general estimation, not an exact figure, i get that but is > there any way to make it more accurate (anyone see a glaring problem with it?) > > thanks, > -Drew > > _______________________________________________ Flow-tools mailing list [email protected] http://mailman.splintered.net/mailman/listinfo/flow-tools
