On 5/10/2016 we cut over to a new broadband Internet access service, switching from Telstra 8Mb/s ADSL to iiNet NBN 12Mb/s.

Over some years, I have run an automated file transfer to measure the speed of our access service. The tests are done between 6:00 and 22:00, I am interested in performance during the times I want to use the service, and less interested in times when I would usually be sleeping.

One of the performance measures is speed, it seems simple enough especially when it is talked about by politicians and promoted by RSPs and NBN’s advertisements.

So, how does one characterise the speed. People like to think of simple concepts like ‘average’, but let us look at the distribution of speeds.

Above is a chart of the frequency distribution of speed observations for a week in March 2017. It is not in the form of the Normal Distribution, the classic bell-shaped curve for which common parametric statistics like Mean (average) and Standard Distribution are meaningful, but it is a skewed distribution. Without knowing the characteristics of the distribution, it is a misuse of parametric statistics to apply parametric statistics like Mean (average) and Standard Distribution. Continue reading Review of 10 months of iiNet broadband Internet access