On Sat, Jun 02, 2001 at 11:17:48PM -0400, Richard A. Steenbergen wrote:
There are only two ways you can poll the rate, either you poll a "rate" value maintained on the device, or you poll a difference in bytes divide by the length of time between samples to calculate a rate. Either way, if the device does not support polling of the "interface" in question you are pretty screwed.
Not necessarily; you just have to find other ways of measuring, as we did, to good effect.
No matter how you stack it, if you miss a rate sample there is no way to go back and get the data again. You either discard it and lose the ability to bill the customer for it (which demands high availability polling systems), or you make up a number and hope the customer doesn't notice.
No -- there is no need to do that. You don't need a sample for every single five-minute interval during the month to produce a meaningful 95%ile measurement for the month; you just need a representative sample population. You increase the chances of your sample population being representative if you consider lots of samples, but dropping one or two does not mean you lose revenue.
Volume polling does not suffer from this problem.
It does, if you don't have per-customer interface counters. You need to count every packet using some other method, and if you can't count packets, you can't bill for them. Joe