-Our internet provider does usage based billing. Part of the bandwidth -is at a fixed price, the remaining bandwidth is subject to UBB.
- -The UBB works as follows: every sample period the current bandwidth is -calculated. When it is above the UBB rate, the excess is used to build -an average over a month. This average is used to calculate the bill.
- -I do trust the provider however I do not necessarily trust their billing -system. Therefore I need a way to check the bill.
- -Normal usage would be to graph from the 1st of the previous month until -the 1st of the current month. RRDtool does all the calculations, using -CDEF statements. I use bash to collect the prices from a database, then -start the RRDtool script with those variables filled in.
- -The data that I used to create the image has been altered to protect -our privacy and the providers pricing policy (meaning: its bogus data). -It does show however how it works. If I create the graph using correct -values for start and end times, the only difference should be caused by -rounding and by different polling times.
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If you are interested in the script generating this, get it -here.