Contention/Oversubscription maths

[lists at memetic.org (Adam Armstrong)]

On 27/05/2011 15:49, Shaun Bryant wrote:
> I run a WISP, where we have moved customers from 3mb/s to 8mb/s to 
> 20mb/s over the course of 5 years. We do this one tower at a time 
> (about 150 customers) what we have learned is usage grows overtime not 
> with the increase in available bandwidth.  Our Per-Customer-Avg (PCA) 
> stayed about the same with each bump in bandwidth, the avg user does 
> not use more bandwidth because they have more bandwidth or at least 
> not our 1200 customers.
>
> That said we have had our PCA move up more then 30% in the last 7 
> months due mainly to Netflix, the nice thing is this usage is "off 
> peak" for our business customers and as such has not been a concern.
>

Yeah, I fully expect this.

In previous networks I've generally seen a doubling of traffic every 12 
months. Generally the traffic is static during spring/summer, and then 
doubles over 6 months in autumn/winter.

Though, I'm not sure how this will manifest itself with such high access 
speeds.

adam.