Well, a warning to other ISPs - check the burst charge billing!
We have a link to our favorite telco which has a "commit" level. I.e. what we agreed to pay. If we go over that level, even once, then we pay extra for the whole month!!! Yeh, fair?!!
So we run shapers to manage the level carefully, and specifically buy more committed capacity when needed. We have complex systems to ensure that if we do ever hit the commit level (as can happen occasionally) services like VoIP work well, and customers paying for premium service get better throughput, and, importantly, that we know it is happening so we can order more. We even publish how well we are doing!
Now, just to be on the safe side, and avoid them shaping traffic in a somewhat cruder way, we also request they cap the service at a level 5% above the commit. They charge if we exceed the commit, and charge an even high rate if we exceed 5% above the commit so setting at 5% seems sensible.
Well, we have have spotted some new incompetance from them. They are charging (quite a lot) for burst traffic. It should not happen, but I suppose if we have a problem one day or a line is on the wrong LNS and uses lots at a peak time, or something, it is just about possible. If that was all it was we would be simply checking all our stats to confirm if we have a mistake.
But the numpties have only gone and charged us thousands for "over 5%" usage even though there is a cap at 5%. I.e. no way we should be able to exceed the 5% ever!
Needless to say this just proves their metering is flawed and we are disputing all the burst charges.
... To be fair - they are looking in to it and agreed it should not have happened.